i have problem that in showpane Modify and Delete pane3
eventhough clicked delete button for the action but the combobox "Select Book" doesnt update in the list that the deleted book still exist. What happen ? any guide ? thx in advance .

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.sql.*;
import javax.swing.table.*;

public class eric extends JFrame 
{		
 		//============================================================ Start Variables ==========
		/////////////////////////////////////////////////////////////////////////////////////////
		boolean inAnApplet = true;   
		final boolean shouldFill = true;
    	final boolean shouldWeightX = true;
				
		//Login panel TAB
		final static String MYPANEL1 = " LOGIN ";
		
		//Student Detail panel TAB		
		final static String MYPANEL2 = " ADD BOOK DETAILS ";
		
		//Modify or Delete Student Details panel TAB		
		final static String MYPANEL3 = " MODIFY / DELETE STUDENT DETAILS ";
		
		//Student Reports panel TAB		
		final static String MYPANEL4 = " BOOK REPORTS ";
		
		//Search student details panel TAB		
		//final static String MYPANEL5 = " SEARCH STUDENT DETAILS ";
		
		//View Student Details panel TAB		
		final static String MYPANEL6 = " VIEW STUDENT DETAILS ";
		
		//General Reports panel TAB		
		final static String MYPANEL7 = " GENERATE REPORTS ";

		//General Reports panel TAB		
		final static String MYPANEL8 = " ADD USERS ";
		
		//First Image to Load is declared as steam.gif to welcome user	
		String imagename = "steam.gif";
		ImageIcon ii = new ImageIcon(imagename);
		
		//I Prefer courier new fonts whereever possible		
		Font dataFont = new Font("courier new",Font.PLAIN,12);
		Font titleFont = new Font("courier new",Font.BOLD,14);
		
		//Required to handle Radio buttons Event
		ActionListener rlistener = new RadioListener();	
		
		//Required to handle Check Box Event
		CheckBoxListener myListener = new CheckBoxListener();
		
		//Required to handle Combo Box Events
		ComboBoxListener cbListener = new ComboBoxListener();
		
		//I prefer gridbag layout (more flexible to place Elements inside a Tab)
		GridBagLayout gridbag = new GridBagLayout();
        GridBagConstraints c = new GridBagConstraints();	
		GridBagConstraints c2 = new GridBagConstraints();	
		GridBagConstraints c5 = new GridBagConstraints();	
		
		//I need a Dialog Box to ask delete confirmation messages etc..
		Container contentPane = getContentPane();		
		JDialog dialog = new JDialog((Frame) null, "! DELETE CONFIRMATION !", true);
		Container dialogContentPane = dialog.getContentPane();		
		
		//Radio Buttons need to be grouped so that u check on one other gets unchecked
		ButtonGroup bg = new ButtonGroup();
		ButtonGroup bg2 = new ButtonGroup();
		ButtonGroup bgq = new ButtonGroup();
		
		// Declare All Labels i will be using somewhere or the other
		JLabel jLabel, jLabel1, jLabel2, jLabel3, jLabel4, jLabel5, jLabel6, jLabel7;
		JLabel jLabel77, jLabel8, jLabel9, jLabelim;
		JLabel jLabeldlg = new JLabel("Do You Really want to Delete ?");
		JLabel jLabelq1, jLabelq2;
		
		// Declare All Radiobuttons i will be using somewhere or the other
		JRadioButton jRadiobutton, Male, Female, mMale, mFemale;		
		JRadioButton jRadiobuttonq1, jRadiobuttonq2;
		
		// Declare All Checkboxes i will be using somewhere or the other
		JCheckBox jCheckbox, SSLC, PHOTO, CHARCERT, NCCCERT, mSSLC, mPHOTO, mCHARCERT, mNCCCERT;	
		JCheckBox jCheckboxq1, jCheckboxq2, jCheckboxq3, jCheckboxq4, jCheckboxq5;
		
		// Declare All Comboboxes i will be using somewhere or the other
		JComboBox jCombobox, jCombobox1, jCombobox2 ,mjCombobox1, mjCombobox2, jCombobox3;	
		JComboBox jComboboxq1, jComboboxq2;
		
		// Declare All Textboxes i will be using somewhere or the other
		JTextField jTextfield;		
		JTextField loginname = new JTextField(40);	
		JTextField loginpass = new JTextField(40);	
		JTextField adds_name = new JTextField(20);	
		JTextField adds_addr = new JTextField(20);	
		JTextField adds_imname = new JTextField(20);						
		JTextField adds_fname = new JTextField(20);		
		JTextField mods_fname = new JTextField(20);		
		JTextField mods_name = new JTextField(20);	
		JTextField mods_addr = new JTextField(20);		
				
		// All String type variables
		String driver="sun.jdbc.odbc.JdbcOdbcDriver";
		String url="jdbc:odbc:eric";		
		String dialogtitle = "Student Record Added";
		String dialogf = "LOGIN FAILED";
		String dialogm = "DATABASE RECORD UPDATED";
		String dialogd = "DATABASE RECORD DELETED";
		String Sexsel = "Male";
		String Yearsel = "1st Collection";
		String Sectionsel = "Section A";
		String currname = "";
		String tempname = "";
		String qry = "";
		String condsel="No Condition", Combo1sel="StudentID", Combo2sel="=";	
		String sql, sql1, dialogmessage, sr, Namesel, reg_no;
		
		// All Integer type variables
		int SSLCsel, PHOTOsel, CHARCERTsel, NCCCERTsel, mSSLCsel, mPHOTOsel, mCHARCERTsel, mNCCCERTsel;
		int dialogtype = JOptionPane.PLAIN_MESSAGE;
		int tempcnt;
		int StudentIDsel=0,StudentNamesel=0,Addresssel=0,FathersNamesel=0,qSexsel=0;
		
		//Declaring all JPanel & Tabbed panes to be used
		JPanel jPanel, p1, p2, p3;
		JTabbedPane tabbedPane = new JTabbedPane();
		
		// Declare All Submit Buttons i will be using somewhere or the other		
		JButton login = new JButton("LOGIN");
		JButton DELETEIT = new JButton("YES DELETE");
		JButton DONTDELETE = new JButton("NO DELETE");
		JButton button, ADDREC, MODIFY, SHOW_STUDENT_LIST, DELETE;
		JButton QUERY;
		
		//Required to Build a JTable in Student Reports (also known as DataGrid by VC++ Users)
		Object[] data = new Object[5];
	   	DefaultTableModel defaulttablemodel = new DefaultTableModel();
   		JTable jtable = new JTable(defaulttablemodel);	
				
		// Declare Textarea i will be using to show query result
		JTextField givencondition;		
		JTextArea resultArea;		
												
		//------------------------------------------------------------ End Variables ------------
		/////////////////////////////////////////////////////////////////////////////////////////
		//============================================================ Start main ===============
		public static void main(String args[])
 		{
  			eric app = new eric();
 		}
		//------------------------------------------------------------ End main -----------------
		//============================================================ Start eric =========
 		public eric() 
 		{
			// Declare Title to my Application 
  			super("Simple Book System v1.0"); 
  			setup();
  			pack();
  			addWindowListener(new WindowEventHandler());
  			show();
 		}
		//------------------------------------------------------------ End eric ------------
		//============================================================ Start setup ===============
 		void setup() 
 		{
  			setupMenuBar(); //Call "setupMenuBar()" to Build the Exit Menu
			showpane1();	//Call some method to Build the Exit Menu
			contentPane.add(tabbedPane, BorderLayout.CENTER);
  		}
		//------------------------------------------------------------ End setup -----------------
		//============================================================ Start setupMenuBar ========
 		void setupMenuBar() 
		{
  			  MenuBar menuBar = new MenuBar();
			  // Main Menu will be "File"
			  Menu fileMenu = new Menu("File");		
			  		// Sub menu under it will be "Exit"	  		
			  		MenuItem fileExit = new MenuItem("Exit");		
						// Handle this submenu item clcik event to Exit 	  			  
			  			fileExit.addActionListener(new MenuItemHandler()); 
			  			fileMenu.add(fileExit);					
			  		menuBar.add(fileMenu);
			  setMenuBar(menuBar);
 		}	
		//------------------------------------------------------------ End setupMenuBar-----------
		//============================================================ Start showpane1 ============		
		void showpane1()
		{
			p1 = new JPanel() //LOGIN TAB
			{
	                public Dimension getPreferredSize() 
					{
	                	Dimension size = super.getPreferredSize();
						// i set width=785 & height=495 for my login TAB & OTHER TABS will use it
	                	size.width = 785;	
						size.height = 495;	
	                	return size;
	            	}
	        };	
			p1.setBorder(BorderFactory.createTitledBorder(BorderFactory.createEtchedBorder(),"Login Panel"));
			p1.setFont(titleFont);
			p1.setLayout(gridbag);  						
			   	jLabel1 = new JLabel("Enter Username : ");
				jLabel1.setFont(dataFont);// Make this Data Font that we declared before
				    //c.weightx = 0.0;    //Horizontal Space not required here		             						
			        c.weighty = 0.0;   	  //Vertical Space	
					c.ipady = 2;       	  //Height of Component				
					c.ipadx = 2; 		  //Width of Component
			        c.anchor = GridBagConstraints.WEST; 	
			      	c.gridwidth = 1;   	  //1 columns wide				
			        c.gridx = 0;       	  //aligned with button 0  -- Very Important 					   
			        c.gridy = 0;       	  //0th Row  -- Very Important 	
					// Add all these features to this Label "jLabel1"	
			        gridbag.setConstraints(jLabel1, c);
					// Add this featured Label "jLabel1" into out LOGIN TAB
		        p1.add(jLabel1);				
				loginname = new JTextField("                                           ");
			    	c.ipady = 2;       						
					c.ipadx = 2;       						
		        	c.weighty = 0.0;   						
		        	c.anchor = GridBagConstraints.WEST; 	
		       		c.gridwidth = 2;   						
		        	c.gridx = 1;       						    
		        	c.gridy = 0;       						
		        	gridbag.setConstraints(loginname, c);
		        p1.add(loginname);				
				jLabel2 = new JLabel("Enter Password : ");
				jLabel2.setFont(dataFont);
			        c.ipady = 2;       						
					c.ipadx = 2;       						
			        c.weighty = 0.0;   						
			        c.anchor = GridBagConstraints.WEST; 	
			        c.gridwidth = 1;   						
			        c.gridx = 0;       						     
			        c.gridy = 1;       						
			        gridbag.setConstraints(jLabel2, c);
			     p1.add(jLabel2);				
				loginpass = new JTextField("                                           ");
			    	c.ipady = 2;       						
					c.ipadx = 2;       						
		        	c.weighty = 0.0;   						
		        	c.anchor = GridBagConstraints.WEST; 	
		       		c.gridwidth = 2;   						
		        	c.gridx = 1;       						     
		        	c.gridy = 1;       						
		        	gridbag.setConstraints(loginpass, c);
		        p1.add(loginpass);				
				button = new JButton("LOGIN");
		        	c.ipady = 2;       						
					c.ipadx = 2;       						
		        	c.weighty = 0.0;   						
		        	c.anchor = GridBagConstraints.CENTER; 	        
					c.gridwidth = 1;   						
		        	c.gridx = 1;       						      
		        	c.gridy = 2;       						
		        	gridbag.setConstraints(button, c);
		        p1.add(button);										
				button.addActionListener(new ButtonHandler());  				
			tabbedPane.addTab(MYPANEL1, p1);
		}
		//------------------------------------------------------------ End__ showpane1 -----------
		//============================================================ Start showpane2 ===========
		void showpane2() //ADD STUDENT  DETAILS TAB 
		{			
				   p2 = new JPanel();
				   p2.setBorder(BorderFactory.createTitledBorder(BorderFactory.createEtchedBorder(),"Add Student Details"));
				   p2.setLayout(gridbag);					  		   
				   jLabel3 = new JLabel(" Book Name : ");	
						jLabel3.setFont(dataFont);		
						c.fill = GridBagConstraints.BOTH;		
						c.ipady = 2;       						
						c.ipadx = 2;  
						c.gridx = 0;       						     
			        	c.gridy = 1;       						
			        	gridbag.setConstraints(jLabel3, c);				
					p2.add(jLabel3);															
						c.ipady = 2;       						
						c.ipadx = 2;  
						c.gridx = 1;       						     
			        	c.gridy = 1;       						
			        	gridbag.setConstraints(adds_name, c);				
					p2.add(adds_name);									
					jLabel4 = new JLabel(" ISBN : ");	
						jLabel4.setFont(dataFont);				
						c.ipady = 2;       						
						c.ipadx = 2;  
						c.gridx = 0;       						     
			        	c.gridy = 2;       						
			        	gridbag.setConstraints(jLabel4, c);		
					p2.add(jLabel4);																		  
						c.ipady = 2;       						
						c.ipadx = 2;  
						c.gridx = 1;       						     
			        	c.gridy = 2;   
						gridbag.setConstraints(adds_addr, c);	
					p2.add(adds_addr);						
					jLabel5 = new JLabel(" Author's Name : ");	
						jLabel5.setFont(dataFont);				
						c.ipady = 2;       						
						c.ipadx = 2;  
						c.gridx = 0;       						     
			        	c.gridy = 3;       						
			        	gridbag.setConstraints(jLabel5, c);				
					p2.add(jLabel5);											
						c.ipady = 2;       						
						c.ipadx = 2;  
						c.gridx = 1;       						     
			        	c.gridy = 3;       						
			        	gridbag.setConstraints(adds_fname, c);				
					p2.add(adds_fname);				
					
					Male = new JRadioButton("Male",true);
						Male.setFont(dataFont);		
						c.fill = GridBagConstraints.BOTH;
						c.ipady = 2;       						
		       			c.ipadx = 2;  
		       			c.gridx = 1;
		        		c.gridy = 4;
		        		gridbag.setConstraints(Male, c);
						Male.addActionListener(rlistener);
						bg.add(Male);
					p2.add(Male);										
	   				Female = new JRadioButton("Female",false);
						Female.setFont(dataFont);		
						c.fill = GridBagConstraints.BOTH;
						c.ipady = 2;       						
		       			c.ipadx = 2;  
		       			c.gridx = 2;
		        		c.gridy = 4;
		        		gridbag.setConstraints(Female, c);								
						Female.addActionListener(rlistener);	
						bg.add(Female);
					p2.add(Female);								
					jLabel6 = new JLabel(" Type : ");	
						jLabel6.setFont(dataFont);				
						c.ipady = 2;       						
						c.ipadx = 2;  
						c.gridx = 0;       						     
			        	c.gridy = 5;       						
			        	gridbag.setConstraints(jLabel6, c);				
					p2.add(jLabel6);													
					jCombobox1 = new JComboBox();
						
						jCombobox1.setFont(dataFont);	
						
				 		jCombobox1.addItem("1st Collection");
		    			jCombobox1.addItem("2nd Sales");
					jCombobox1.addItem("3rd Rent");
						
		    			c.fill = GridBagConstraints.BOTH;
						c.insets = new Insets(10,0,0,30);  		
						c.ipady = 2;     						
						c.ipadx = 2;							
		       	        c.gridx = 1;							
		        		c.gridy = 5;							
						jCombobox1.addItemListener(cbListener);	
		        		gridbag.setConstraints(jCombobox1, c);
		        	p2.add(jCombobox1);							
					jLabelim = new JLabel(" Image Name : ");	
						jLabelim.setFont(dataFont);				
						c.ipady = 2;       						
						c.ipadx = 2;  
						c.gridx = 0;       						     
			        	c.gridy = 8;       						
			        	gridbag.setConstraints(jLabelim, c);				
					p2.add(jLabelim);							
							c.ipady = 2;       						
							c.ipadx = 2;  
							c.gridx = 1;       						     
			        		c.gridy = 8;   			  						
			        		gridbag.setConstraints(adds_imname, c);				
					p2.add(adds_imname);																	
					ADDREC = new JButton("SAVE RECORD");										
						c.ipady = 2;       						
						c.ipadx = 2;  
						c.gridx = 2;       						     
			        	c.gridy = 8;  
						gridbag.setConstraints(ADDREC, c);	
						// Handle "SAVERECORD" button clicked event by "ButtonHandler()"					
						ADDREC.addActionListener(new ButtonHandler());
					p2.add(ADDREC);
					jLabel7 = new JLabel(" ", ii, JLabel.CENTER);	
						c.fill = GridBagConstraints.BOTH;
						c.gridwidth = 5; 
						c.gridx = 0;       						     
			        	c.gridy = 9;       						
			        	gridbag.setConstraints(jLabel7, c);				
					p2.add(jLabel7);				   
				tabbedPane.addTab(MYPANEL2, p2);
		}
		//-------------------------------------------------------------- End showpane2 ---------
		//============================================================ Start showpane3 =========
		void showpane3() //MODIFY STUDENT DETAILS TAB
		{			  	   
				   p3 = new JPanel();
				   p3.setBorder(BorderFactory.createTitledBorder(BorderFactory.createEtchedBorder(),"Modify Student Details"));
				   p3.setLayout(gridbag);	
				   jCombobox3 = new JComboBox();
				   		jCombobox3.addItem("Select Book : ");
						jCombobox3.setFont(dataFont);	
						c2.fill = GridBagConstraints.BOTH;		
						c2.ipady = 2;       						
						c2.ipadx = 2;  
						c2.gridx = 2;       						     
			        	c2.gridy = 1;       						
			        	gridbag.setConstraints(jCombobox3, c2);			
						jCombobox3.addItemListener(cbListener);		
					p3.add(jCombobox3);		
				   JLabel jl8 = new JLabel(" Book Name : ");
						jl8.setFont(dataFont);		
						c2.fill = GridBagConstraints.BOTH;		
						c2.ipady = 2;       						
						c2.ipadx = 2;  
						c2.gridx = 0;       						     
			        	c2.gridy = 1;       						
			        	gridbag.setConstraints(jl8, c2);				
					p3.add(jl8);				
					mods_name = new JTextField(20);	
						c2.ipady = 2;       						
						c2.ipadx = 2;  
						c2.gridx = 1;       						     
			        	c2.gridy = 1;       						
			        	gridbag.setConstraints(mods_name, c2);				
					p3.add(mods_name);	
					JLabel jl9 = new JLabel(" ISBN : ");
						jl9.setFont(dataFont);		
						c2.fill = GridBagConstraints.BOTH;		
						c2.ipady = 2;       						
						c2.ipadx = 2;    
						c2.gridx = 0;       						     
			        	c2.gridy = 2;       						
			        	gridbag.setConstraints(jl9, c2);				
					p3.add(jl9);		
					mods_addr = new JTextField(20);	
						c2.ipady = 2;       						
						c2.ipadx = 2;  
						c2.gridx = 1;       						     
			        	c2.gridy = 2;       						
			        	gridbag.setConstraints(mods_addr, c2);				
					p3.add(mods_addr);				
					jLabel5 = new JLabel(" Author's Name : ");	
						jLabel5.setFont(dataFont);				
						c2.ipady = 2;       						
						c2.ipadx = 2;  
						c2.gridx = 0;       						     
			        	c2.gridy = 3;       						
			        	gridbag.setConstraints(jLabel5, c2);				
					p3.add(jLabel5);											
						c2.ipady = 2;       						
						c2.ipadx = 2;  
						c2.gridx = 1;       						     
			        	c2.gridy = 3;       						
			        	gridbag.setConstraints(mods_fname, c2);				
					p3.add(mods_fname);												
					mMale = new JRadioButton("Male",true);
						mMale.setFont(dataFont);		
						c2.fill = GridBagConstraints.BOTH;
						c2.ipady = 2;       						
		       			c2.ipadx = 2;  
		       			c2.gridx = 1;
		        		c2.gridy = 4;
		        		gridbag.setConstraints(mMale, c2);
						mMale.addActionListener(rlistener);
						bg2.add(mMale);
					p3.add(mMale);										
	   				mFemale = new JRadioButton("Female",false);
						mFemale.setFont(dataFont);		
						c2.fill = GridBagConstraints.BOTH;
						c2.ipady = 2;       						
		       			c2.ipadx = 2;  
		       			c2.gridx = 2;
		        		c2.gridy = 4;
		        		gridbag.setConstraints(mFemale, c2);
						bg2.add(mFemale);		
						mFemale.addActionListener(rlistener);	
					p3.add(mFemale);								
					jLabel6 = new JLabel(" Type : ");	
						jLabel6.setFont(dataFont);				
						c2.ipady = 2;       						
						c2.ipadx = 2;  
						c2.gridx = 0;       						     
			        	c2.gridy = 5;       						
			        	gridbag.setConstraints(jLabel6, c2);				
					p3.add(jLabel6);													
					mjCombobox1 = new JComboBox();
						mjCombobox1.setFont(dataFont);	
				 		mjCombobox1.addItem("1st Collection");
		    			mjCombobox1.addItem("2nd Sales");
					mjCombobox1.addItem("3rd Rent");
		    			c2.fill = GridBagConstraints.BOTH;
						c2.insets = new Insets(10,0,0,30);  		
						c2.ipady = 2;     						
						c2.ipadx = 2;							
		       	        c2.gridx = 1;							
		        		c2.gridy = 5;							
						mjCombobox1.addItemListener(cbListener);	
		        		gridbag.setConstraints(mjCombobox1, c2);
		        	p3.add(mjCombobox1);							
					DELETE = new JButton("DELETE RECORD");										
						c2.ipady = 2;       						
						c2.ipadx = 2;  
						c2.gridx = 1;       						     
			        	c2.gridy = 8;  
						gridbag.setConstraints(DELETE, c2);
						p3.add(DELETE);
						DELETE.addActionListener(new ButtonHandler());											
					MODIFY = new JButton("MODIFY RECORD");										
						c2.ipady = 2;       						
						c2.ipadx = 2;  
						c2.gridx = 2;       						     
			        	c2.gridy = 8;  
						gridbag.setConstraints(MODIFY, c2);
						p3.add(MODIFY);
						MODIFY.addActionListener(new ButtonHandler());					
					jLabel7 = new JLabel(" ", ii, JLabel.CENTER);	
						c2.fill = GridBagConstraints.BOTH;
						c2.gridwidth = 5; 
						c2.gridx = 0;       						     
			        	c2.gridy = 10;       						
			        	gridbag.setConstraints(jLabel7, c2);				
					p3.add(jLabel7);					
			tabbedPane.addTab(MYPANEL3, p3);	
			accessDBinit();
		}
		//-------------------------------------------------------------- End showpane3 ---------
		//============================================================ Start showpane4 =========
		void showpane4() // REPORTS TAB WITH JTABLE
		{
			  JPanel p4 = new JPanel();			
			  p4.setBorder(BorderFactory.createTitledBorder(BorderFactory.createEtchedBorder(),"Student Reports"));
			  try
			  {			  					
					Class.forName(driver);					
			   		Connection connection=DriverManager.getConnection(url);
			   		Statement statement = connection.createStatement();	
					String query = "SELECT StudentID AS BookID, Name AS BookName, Address AS ISBN, FName AS AuthorName FROM book_det";
					ResultSet rs = statement.executeQuery(query);	
					ResultSetMetaData rmeta = rs.getMetaData();
					int numColumns=rmeta.getColumnCount();					
					for(int i=1;i<=numColumns;++i) 
					{
   						if(i<=numColumns)
						{
							defaulttablemodel.addColumn(rmeta.getColumnName(i));
						}   					
  					}					
					while(rs.next())
					{   						
						for(int i=1;i<=numColumns;++i)   
						{		
							if(i<=numColumns)
							{				 	
								tempname = rs.getString(i);
								tempcnt=i-1;
								data[tempcnt] = tempname;		
							}			
	   					}   
						defaulttablemodel.addRow(data);						
   					}
			  }
			  catch(Exception ex)
			  {
			  		//
			  }
	        p4.add(new JScrollPane(jtable));
			tabbedPane.addTab(MYPANEL4, p4);
		}		
		//------------------------------------------------------------ End showpane4 ------------
		//============================================================= Start showpane6 =========
		void showpane6()	//FOR FUTURE USE BY USER PRINCIPAL
		{			
			JPanel p6 = new JPanel();
				jLabel = new JLabel(" Inside Panel 6 ");	
				p6.add(jLabel);
			tabbedPane.addTab(MYPANEL6, p6);
		}
		//------------------------------------------------------------ End showpane6 ------------
		void showpane2345() 
		{	
			showpane2();
			showpane3();
			showpane4();
			showpane8();
		}
		void showpane67()	
		{	
			showpane6();
			//showpane7();
		}

		//============================================================= Start showpane8 =========
		void showpane8()  //FOR FUTURE USE BY USER PRINCIPAL
		{
			JPanel p8 = new JPanel();
				jLabel = new JLabel(" Inside Panel 8 ");	
				p8.add(jLabel);
			tabbedPane.addTab(MYPANEL8, p8);
		}	
		/////////////////////////////////////////////////////////////////////////////////////////
		//========================================================== Start accessDB() =============	
		void accessDB() 
		{		 	
			  try
			  {			   		
					String var1 =  loginname.getText();
						   var1 =  var1.trim();
					String var2 =  loginpass.getText();
						   var2 =  var2.trim();		
					//JDBC step 1 :  Write your SQL (structured query language)			
					sql = "SELECT * FROM login WHERE username='"+var1+"' AND password='"+var2+"'";
					//JDBC step 2 : using driver="sun.jdbc.odbc.JdbcOdbcDriver"; for MSACCESS
					Class.forName(driver);
					//JDBC step 3 : using driver="sun.jdbc.odbc.JdbcOdbcDriver";
			   		Connection connection=DriverManager.getConnection(url);
					//JDBC step 4 : url="jdbc:odbc:eric";	ODBC Comes into picture here
			   		Statement statement = connection.createStatement();
					//JDBC step 5 : Get JDBC connection
					boolean hasResults = statement.execute(sql);
					//JDBC step 6 : Execute your SQL (see if it has any results)
			   		if(hasResults)
					{
			    		ResultSet result = statement.getResultSet();
						//JDBC step 7 : if there are results Get the "SET" 
			    		if(result!=null)
						{ 	
							//take this "SET" of results from "SQL"
							//call this method "isplayResults(ResultSet r)" and pass ResultSet to it 
							displayResults(result);
			   			}
						//JDBC step 8 : Close Database Connection u Established
						connection.close();
			  		}				
			  }
			  catch(Exception ex)
			  {

			  }
		}	
		void displayResults(ResultSet r) throws SQLException 
		{
  				ResultSetMetaData rmeta = r.getMetaData();
				//Get Metadata from resultset 
				int foundrec = 0;
  				int numColumns=rmeta.getColumnCount();  
				while(r.next())
				{								
						String param3 = r.getString(3).trim();
						// 3rd field in the table 'login' , database 'eric.mdb'						
						if (param3.equals("Accounts")) 
						{
							// for login 'a' , password 'a' , if his deparment is "Accounts"
						    // u found record , so set foundrecord = 1
							foundrec = 1;
							//remove login TAB
							tabbedPane.removeTabAt(0);
							// Show other panes 2-3-4-5
							showpane2345();	
						}
						else if(param3.equals("Principal"))
						{
							// for login 'p' , password 'p' , if his deparment is "Principal" 
							// u found record , so set foundrecord = 1
							foundrec = 1;
							//remove login TAB (TAB 0)
							tabbedPane.removeTabAt(0);
							showpane67();	
						}		
  				}		
				if(foundrec==0)
				{
					//if foundrecord is zero , invalid login
					dialogmessage = "Please Re-Login";
					dialogtype = JOptionPane.INFORMATION_MESSAGE;
					//show message
					JOptionPane.showMessageDialog((Component) null, dialogmessage, dialogf, dialogtype);
					//make login and password textboxes empty
					loginname.setText(" ");
					loginpass.setText(" ");
				}	
		}	
		//------------------------------------------------------------------- End accessDB() -------	
		//=================================================================== Start accessDBADD()====
		void accessDBADD() 
		{
		 	  try
			  {			  
					Class.forName(driver);					
			   		Connection connection=DriverManager.getConnection(url);
			   		Statement statement = connection.createStatement();	
					//Generate new register number
					String query = "SELECT * FROM book_det";
					ResultSet rs = statement.executeQuery(query);
					int cnt = 0;
					while (rs.next()) 
					{
    					cnt++;      					
					}
					cnt = cnt+1;
					//char ys = Yearsel.charAt(0);
					//char ss =  Sectionsel.charAt(8);
					reg_no = "11-Eric-"+cnt; 
					//insert data with new reg no and other details
					sql = "INSERT INTO book_det (StudentID, Name, Address, FName, Sex, Yearsel, Sectionsel, imagename) VALUES ('"+reg_no+"','"+adds_name.getText()+"','"+adds_addr.getText()+"','"+adds_fname.getText()+"','"+Sexsel+"','"+Yearsel+"','"+Sectionsel+"','"+adds_imname.getText()+"')"; 
					statement.executeUpdate(sql);	
					connection.close();	
					// add this new record to our JTable too (DATAGRID)									
					data[0] = reg_no;		
					data[1] = adds_name.getText();	
					data[2] = adds_addr.getText();		
					data[3] = adds_fname.getText();			 
					defaulttablemodel.addRow(data);
					dialogmessage = " "+adds_name.getText().toUpperCase()+" has Registration Number : "+reg_no;
					dialogtype = JOptionPane.INFORMATION_MESSAGE;
					//show user the new register number and new record holder name
					JOptionPane.showMessageDialog((Component) null, dialogmessage, dialogtitle, dialogtype);
					//rollback combobox selection
					jCombobox1.setSelectedIndex(0);  //section 
					//jCombobox2.setSelectedIndex(0);  //standard 
					
					String snametemp = adds_name.getText();
					jCombobox3.addItem(adds_name.getText());
					// add name to combobox in modify names TAB
					
					//set other textboxes black to enable new record entry
					adds_name.setText(" ");
					adds_addr.setText(" ");
					adds_fname.setText(" ");
					adds_imname.setText(" ");
					
					// uncheck checkboxes if they are checked while adding data
					//SSLC.setSelected(false);
					//PHOTO.setSelected(false);
					//NCCCERT.setSelected(false);
					//CHARCERT.setSelected(false);
					
					//click on the radiobutton male , to make it default again
					Male.doClick();		
			  }
			  catch(Exception ex)
			  {

			  }
		}
		//------------------------------------------------------------------- End accessDBADD() -------	
		//=============================================================== Start accessDBMod() ========	
		void accessDBMod(String nsel) 
		{		 	
			  try
			  {			   	
					sql = "SELECT * FROM book_det WHERE Name='"+nsel+"'";
					Class.forName(driver);
			   		Connection connection=DriverManager.getConnection(url);
			   		Statement statement = connection.createStatement();
					boolean hasResults = statement.execute(sql);
			   		if(hasResults)
					{
			    		ResultSet result = statement.getResultSet();
			    		if(result!=null)
						{ 		
							displayResultsMod(result);
			   			}
						//connection.Refresh();
						connection.close();
			  		}						
			  }
			  catch(Exception ex)
			  {

			  }
		}	
		void displayResultsMod(ResultSet r) throws SQLException 
		{
  				ResultSetMetaData rmeta = r.getMetaData();
				int foundrec = 0;
  				int numColumns=rmeta.getColumnCount();
				String text2="";	
				String text3="";	
				String text4="";	
				String text5="";	
				String text6="";	
				String text7="";	
				String text8="";	
				int int9=0;
				int int10=0;
				int int11=0;
				int int12=0;
				while(r.next())
				{
					reg_no=r.getString(2);
  					text3+=r.getString(3);
					text4+=r.getString(4);
					text5+=r.getString(5);
					text6+=r.getString(6);
					text7+=r.getString(7);
					text8+=r.getString(8);
					int9=r.getInt(9);
					int10=r.getInt(10);
					int11=r.getInt(11);
					int12=r.getInt(12);		
					imagename=r.getString(13);
  				}
				jLabel7.setIcon(new ImageIcon(imagename));
				currname = text3;				
				mods_name.setText(text3);
				mods_addr.setText(text4);
				mods_fname.setText(text5);				
				text6 = text6.trim();
				if (text6.equals("Male")) 
				{
					mMale.doClick();						
				}
				else
				{
					mFemale.doClick();
				}	
				
				text7 = text7.trim();
				if (text7.equals("2nd Sales")) 
				{
					mjCombobox1.setSelectedIndex(1); 			
				}
				else if(text7.equals("1st Collection")) 
				{
					mjCombobox1.setSelectedIndex(0); 
				}else
				{
					mjCombobox1.setSelectedIndex(2); 
				}
				
				//jCombobox1.addItem("1st Collection");
		    			//jCombobox1.addItem("2nd Sales");
					//jCombobox1.addItem("3rd Rent");
				/*text8 = text8.trim();
				if (text8.equals("Section A")) 
				{
					mjCombobox2.setSelectedIndex(0); 			
				}
				else if(text8.equals("Section B"))
				{
					mjCombobox2.setSelectedIndex(1); 
				}				
				else
				{
					mjCombobox2.setSelectedIndex(2); 
				}		
				if(int9==1)
				{
					mSSLC.setSelected(true);
				}
				else
				{
					mSSLC.setSelected(false);
				}
				if(int10==1)
				{
					mPHOTO.setSelected(true);
				}
				else
				{
					mPHOTO.setSelected(false);
				}
				if(int11==1)
				{
					mCHARCERT.setSelected(true);
				}
				else
				{
					mCHARCERT.setSelected(false);
				}
				if(int12==1)
				{
					mNCCCERT.setSelected(true);
				}
				else
				{
					mNCCCERT.setSelected(false);
				}*/
		}
		//------------------------------------------------------------- End accessDBMod() --------	
		//============================================================= Start accessDBinit()=======
		void accessDBinit() 
		{
		 	  try
			  {			  		
					sql = "SELECT Name FROM book_det ORDER BY Name"; 
					Class.forName(driver);
			   		Connection connection=DriverManager.getConnection(url);
			   		Statement statement = connection.createStatement();
					boolean hasResults = statement.execute(sql);
					if(hasResults)
					{
			    		ResultSet result = statement.getResultSet();
			    		if(result!=null)
						{ 							
							displayResultsinit(result);
						}						
			   			connection.close();
			  		}
				
			  }
			  catch(Exception ex)
			  {
			   		
			  }
		}
		void displayResultsinit(ResultSet r) throws SQLException 
		{
  				ResultSetMetaData rmeta = r.getMetaData();
  				int numColumns=rmeta.getColumnCount(); 
				while(r.next())
				{	
					for(int i=1;i<=numColumns;++i) 
					{
    					if(i<=numColumns)
						{
							jCombobox3.addItem(r.getString(i));
						}
   					}   					 
  				}	
		}
		//------------------------------------------------------------- End accessDBinit() --------		
		//============================================================= Start accessDBDel()========
		void accessDBDel(String nsel) 
		{		 	
			  try
			  {				
					//em.getTransaction().begin();
	  					
					Class.forName(driver);					
			   		Connection connection=DriverManager.getConnection(url);
			   		Statement statement = connection.createStatement();
					
					sql = "DELETE FROM book_det WHERE Name='"+nsel+"'";
					statement.executeUpdate(sql);	
							
					connection.close();			
					mjCombobox1.setSelectedIndex(0);		 
					//mjCombobox2.setSelectedIndex(0);			 
					mods_name.setText(" ");					
					mods_addr.setText(" ");			
					mods_fname.setText(" ");			
					//mSSLC.setSelected(false);			
					//mPHOTO.setSelected(false);			
					//mNCCCERT.setSelected(false);		
					//mCHARCERT.setSelected(false);		
					mMale.doClick();						
			  }
			  catch(Exception ex)
			  {

			  }
		}	
		//---------------------------------------------------------------- End accessDBDel()-------
		//================================================================= Start updateDB() ======	
		void updateDB() 
		{
		 	  try
			  {
			  		sql = "UPDATE book_det SET Name='"+mods_name.getText()+"', Address='"+mods_addr.getText()+"', FName='"+mods_fname.getText()+"', Sex='"+Sexsel+"', Yearsel='"+Yearsel+"' WHERE StudentID='"+reg_no+"'"; 
					Class.forName(driver);
			   		Connection connection=DriverManager.getConnection(url);
			   		Statement statement = connection.createStatement();
					statement.executeUpdate(sql);	
		   			connection.close();
					dialogmessage = " "+mods_name.getText().toUpperCase()+" Record is Updated ";
					dialogtype = JOptionPane.INFORMATION_MESSAGE;
					JOptionPane.showMessageDialog((Component) null, dialogmessage, dialogm, dialogtype);
			  }
			  catch(Exception ex)
			  {
			  		
			  }			  
		}		
		//----------------------------------------------------------------- End updateDB() ---------
		//============================================================  Start handleQuery() =======
		void handleQuery()
		{
				qry="SELECT";
				int cnt=0;
				if(StudentIDsel==1)
				{
					cnt++;
					qry+=" StudentID,";
				}
				if(StudentNamesel==1)
				{
					cnt++;
					qry+=" Name,";
				}
				if(Addresssel==1)
				{
					cnt++;
					qry+=" Address,";
				}
				if(FathersNamesel==1)
				{
					cnt++;
					qry+=" FName,";
				}
				if(qSexsel==1)
				{
					cnt++;
					qry+=" Sex,";
				}		
				int slen=qry.length();
				int tempslen = slen-1;
				qry = qry.substring(0,tempslen);
				qry+=" FROM book_det";
				if(condsel=="Set Condition")
				{
					qry+=" WHERE "+Combo1sel+" "+Combo2sel+" "+givencondition.getText().trim();
				}
				jLabelq2.setText(qry);
				accessDBquery(qry); 
		}		
		//------------------------------------------------------------  End handleQuery() --------
		//============================================================== Start accessDBquery() ===
		void accessDBquery(String sqlq) 
		{
  			try
			{
   				Class.forName(driver);
	   			Connection connection=DriverManager.getConnection(url);
	   			Statement statement = connection.createStatement();
	   			boolean hasResults = statement.execute(sqlq);
	   			if(hasResults)
				{
	    			ResultSet result = statement.getResultSet();
		    		if(result!=null) 
					{
						displayResultsQ(result);
					}
					else 
					{
						resultArea.setText("");
					}   				
				}
				connection.close();
  			}
			catch(Exception ex)
			{
   				resultArea.setText(ex.toString());
  			}
 		}
		void displayResultsQ(ResultSet r) throws SQLException 
		{
	  		ResultSetMetaData rmeta = r.getMetaData();
	  		int numColumns=rmeta.getColumnCount();
	  		String text="";
	  		for(int i=1;i<=numColumns;++i) 
			{
	   		if(i<numColumns)
	    		text+=rmeta.getColumnName(i)+" | ";
	   		else
	    		text+=rmeta.getColumnName(i);
	  		}
	  		text+="\n";
	  		while(r.next())
			{
	   			for(int i=1;i<=numColumns;++i) 
				{
	    			if(i<numColumns)
	     				text+=r.getString(i)+" | ";
	    			else
	     				text+=r.getString(i).trim();
	   			}
	   			text+="\n";
	  		}
	  		resultArea.setText(text);
	 	}
		//---------------------------------------------------------------- End accessDBquery() ---
		/////////////////////////////////////////////////////////////////////////////////////////
		//============================================================= Start ButtonHandler ========
 		class ButtonHandler implements ActionListener 
		{
  			public void actionPerformed(ActionEvent ev)
			{
   				String s=ev.getActionCommand(); 	
				//see which button is click accordingly call its method			
				if(s=="LOGIN") 
				{
					// call method accessDB();
					accessDB();					
				}  
				else if(s=="SAVE RECORD")
				{
					accessDBADD();
					String snametemp = adds_name.getText();
				}	
				else if(s=="MODIFY RECORD")
				{					
					String temp_mname = mods_name.getText().trim();
					String temp_currname = currname.trim();
					if(temp_mname.equals(temp_currname))
					{
						
					}
					else
					{
						jCombobox3.addItem(mods_name.getText());	
					}					
					updateDB();					
				}
				else if(s=="DELETE RECORD")
				{
					dialogContentPane.setLayout(new FlowLayout());					
					dialogContentPane.add(jLabeldlg);
					jLabeldlg.setFont(titleFont);
					dialogContentPane.add(DELETEIT);
					DELETEIT.addActionListener(new ButtonHandler());		
					dialogContentPane.add(DONTDELETE);
					DONTDELETE.addActionListener(new ButtonHandler());
					//Boundry for this dialog box
					dialog.setBounds(300, 200, 250, 120);
					//show delete confirmation dialog
					dialog.show();
				}
				else if(s=="YES DELETE")
				{
					dialog.dispose();
					Namesel = jCombobox3.getSelectedItem().toString();
  					accessDBDel(Namesel);
					jCombobox3 = new JComboBox();
					ComboBoxListener cbListener = new ComboBoxListener();
					
				}
				else if(s=="NO DELETE")
				{
					dialog.dispose();
				}
				else if(s=="QUERY") 
				{
					handleQuery();					
				}				
			}
 		}
		//------------------------------------------------------------- End ButtonHandler --------	
		//=========================================================== START MenuItemHandler ======
 		class MenuItemHandler implements ActionListener 
		{
  			public void actionPerformed(ActionEvent ev)
			{
   				String s=ev.getActionCommand();
   				if(s=="Exit")
				{
					//close window on menuitem exit
    				System.exit(0);
   				}								
  			}					
 		}
		//----------------------------------------------------------- END__ MenuItemHandler ------
		//=========================================================== START WindowEventHandler ===
 		class WindowEventHandler extends WindowAdapter 
		{
  			public void windowClosing(WindowEvent e)
			{
				//close window on exit
   				System.exit(0);
  			}
 		}
		//----------------------------------------------------------- END__ WindowEventHandler ---
		//=========================================================== START RadioListener ========
		class RadioListener implements ActionListener 
		{
      		public void actionPerformed(ActionEvent e) 
			{
				  Sexsel = e.getActionCommand();
				  condsel = e.getActionCommand();
		    }
		}
		//----------------------------------------------------------- END__ RadioListener --------
		//=========================================================== START RadioListener ========
		class ComboBoxListener implements ItemListener  
		{
      		public void itemStateChanged(ItemEvent e) 
			{				
		    	sr = (String)e.getItem();
				if (e.getSource().equals(jCombobox1))
    			{
    				Yearsel = jCombobox1.getSelectedItem().toString();
    			}
				if (e.getSource().equals(mjCombobox1))
    			{
    				Yearsel = mjCombobox1.getSelectedItem().toString();
    			}
    			if (e.getSource().equals(jCombobox2))
    			{
    				Sectionsel = jCombobox2.getSelectedItem().toString();
    			}
				if (e.getSource().equals(mjCombobox2))
    			{
    				Sectionsel = mjCombobox2.getSelectedItem().toString();
    			}
				if (e.getSource().equals(jCombobox3))
    			{					
					Namesel = jCombobox3.getSelectedItem().toString();					
  					accessDBMod(Namesel);					
    			}
				if (e.getSource().equals(jComboboxq1))
    			{
					Combo1sel = jComboboxq1.getSelectedItem().toString();
    			}
				if (e.getSource().equals(jComboboxq2))
    			{
					Combo2sel = jComboboxq2.getSelectedItem().toString();
    			}
		    }
		}
		//----------------------------------------------------------- END__ RadioListener --------
		//=========================================================== START CheckBoxListener =====		
		class CheckBoxListener implements ItemListener 
		{
    		
			public void itemStateChanged(ItemEvent e) 
    		{
        		Object source = e.getItemSelectable();
				if ((e.getStateChange() == ItemEvent.SELECTED) && (source==jCheckboxq1))
       			{
					StudentIDsel = 1;
      			}
				if ((e.getStateChange() == ItemEvent.DESELECTED)  && (source==jCheckboxq1))
       			{
					StudentIDsel = 0;
      			}	
				if ((e.getStateChange() == ItemEvent.SELECTED) && (source==jCheckboxq2))
       			{
					StudentNamesel = 1;
      			}
				if ((e.getStateChange() == ItemEvent.DESELECTED)  && (source==jCheckboxq2))
       			{
					StudentNamesel = 0;
      			}	
				if ((e.getStateChange() == ItemEvent.SELECTED) && (source==jCheckboxq3))
       			{
					Addresssel = 1;
      			}
				if ((e.getStateChange() == ItemEvent.DESELECTED)  && (source==jCheckboxq3))
       			{
					Addresssel = 0;
      			}	
				if ((e.getStateChange() == ItemEvent.SELECTED) && (source==jCheckboxq4))
       			{
					FathersNamesel = 1;
      			}
				if ((e.getStateChange() == ItemEvent.DESELECTED)  && (source==jCheckboxq4))
       			{
					FathersNamesel = 0;
      			}	
				if ((e.getStateChange() == ItemEvent.SELECTED) && (source==jCheckboxq5))
       			{
					qSexsel = 1;
      			}
				if ((e.getStateChange() == ItemEvent.DESELECTED)  && (source==jCheckboxq5))
       			{
					qSexsel = 0;
      			}	
										
    		}			
		}
		
}

Dear,

Its too difficult to read whole program line by line but I guess you are facing problem due to not closing database connection immediately as soon as a specific database operation is over.

Even if the database is updated you also need to update the comboBox as well by removing the book selected if the deletion was successful.

This article has been dead for over six months. Start a new discussion instead.