if(@$_GET['action'] == "Search"){
$result = mysql_query 
("SELECT * FROM students where
          idnum = '$_GET[mysearch]' or 
          fname = '$_GET[mysearch]' or 
          lname = '$_GET[mysearch]' or
          midin = '$_GET[mysearch]' or 
          gender = '$_GET[mysearch]' or 
          bdate = '$_GET[mysearch]' or
          course = '$_GET[mysearch]' or
          year = '$_GET[mysearch]' or
          address = '$_GET[mysearch]' or
          cnum ='$_GET[mysearch]'");
     $rows = mysql_num_rows($result);
     if ($rows != 0) {
        print "<table border=1 align=center>";
        print "<tr <td class=tdb>
                  <td><font size=3><center>Identification </center></font></td>
                  <td><font size=3><center>First Name</center></font></td>
                  <td><font size=3><center>Last Name</center></font></td>
                  <td><font size=3><center>Middle Initial</center></font></td>
                  <td><font size=3><center>Gender</center></font></td>
                  <td><font size=3><center>Birthdate</center></font></td>
                  <td><font size=3><center>Course</center></font></td>
                  <td><font size=3><center>Year</center></font></td>
                  <td><font size=3><center>Address</center></font></td>
          <td><font size=3><center>Contact Number</center></font></td>
          <td colspan=2><font size=3><center>Action</center></font></td></tr>";
        for ($i=0; $i< $rows; $i++) 
         {
           $row = mysql_fetch_row ($result);
           print "<tr>";
           print "<td><font size=3><center>$row[0]</center></font></td>";
           print "<td><font size=3><center>$row[1]</center></font></td>";
           print "<td><font size=3><center>$row[2]</center></font></td>";
           print "<td><font size=3><center>$row[3]</center></font></td>";
           print "<td><font size=3><center>$row[4]</center></font></td>";
           print "<td><font size=3><center>$row[5]</center></font></td>";
           print "<td><font size=3><center>$row[6]</center></font></td>";
           print "<td><font size=3><center>$row[7]</center></font></td>";
       print "<td><font size=3><center>$row[8]</center></font></td>";
       print "<td><font size=3><center>$row[9]</center></font></td>";
           print "<td>[ <a href=kalvin.php?action=Delete&idnum=$row[0]>Delete</a> ]";
              print "[ <a href=kalvin.php?action=Edit&idnum=$row[0]>Edit</a> ]";
           print "</td>";
           print "</tr>";
         }
        print "</table>";
        print "<font size=5>Number of entries found: $rows<br><button type=button onclick=history.back();>Back</button></font>";
     }
     else {
           print "<font size=5><center><blink>No records found!</blink><br><button type=button onclick=history.back();>Back</button></center></font>";
          }
     mysql_free_result ($result);
  }

Guys how can i modify this to make my search input can input letters and show all in my database containing those letter? :D thanks for any help guys.

You can do one thing use textbox to input letters.
THen retrive textbox value and then put in the like clause of your select query
Ex:

"SELECT * FROM students where
idnum = '$_GET[mysearch]' or 
fname = '$_GET[mysearch]' or 
lname = '$_GET[mysearch]' or
midin = '$_GET[mysearch]' or 
gender = '$_GET[mysearch]' or 
bdate = '$_GET[mysearch]' or
course = '$_GET[mysearch]' or
year = '$_GET[mysearch]' or
address = '$_GET[mysearch]' or
cnum ='$_GET[mysearch]' and fname like '$_GET[textbox_val]"

thanks avinanuami, but what about i constraint the case. if i search lowercase letter it will only show lowercase letter save on database content.