I am new member here I need help with my program.
I am trying to calculate interst for a loan I am not able to calculate last payment for loan like if loan amount is 1000 and interst rate is 18% which come up 1.5% for every month and if there is fix payment of 5% of the starting amount (1000) .
It was running and calculating all other then last payment but now its not even running some one cane help me I realy appreciate thanks.

import javax.swing.JOptionPane;
import java.awt.Container;
import javax.swing.*;
public class payment1 {

// main method begins execution of Java application
public static void main( String args[] )
float Interst,Payment,MonthInterst,TotalInterst=0,MonthlyNetPay,FinalPayment=0;
float monthlypay ,MonthsInterst;
String output,interstvalue,paymentvalue;
int months=0;

paymentvalue =
JOptionPane.showInputDialog( "Please enter the amount:" );

interstvalue =
JOptionPane.showInputDialog( "Please enter the interst rate" );

Payment = Float.parseFloat( paymentvalue);
Interst = Float.parseFloat( interstvalue );

output="The payment amount:"+Payment+"\nThe Interst is:"+Interst;
monthlypay= (5/100) * Payment;

while(Payment > 0)  {

MonthsInterst = Interst/12;
MonthInterst= ((MonthsInterst/100)* Payment);

TotalInterst = TotalInterst + MonthInterst;
MonthlyNetPay = monthlypay - MonthInterst;
Payment = Payment - MonthlyNetPay;

if (MonthlyNetPay >= Payment) {
FinalPayment = Payment;



output +="\nTotal Interst:"+TotalInterst+"\nThe Last Payment:"+FinalPayment;

JTextArea outputArea = new JTextArea();
outputArea.setText( output);

JOptionPane.showMessageDialog( null, outputArea,
"Grade Printing Program",

System.exit( 0 );

Your code is impossible to read ... no indentation ... no code tags ... no spacing ... no nothing ....