how to know which jList is selected and according to that fetch the value

Hi. I am Using netBeans..

I have 4 JLists (i.e jList1 , jList2, jList3 , jList4) in 4 different tabs in frame.

Each List has the value of employee_id from database (i successfully did it already) there are many field in tabs ( i.e rows of databse with employee id as primary key)

How to know which jList is selected so that i get the value of employee_id from the correct jList (i.e which is selected) to fetch data from database using selected employee id from selected jList with a common handler

A part of my program is

private void get_empid_detail(java.awt.event.MouseEvent evt) {                                  
   try {

   Class.forName("com.mysql.jdbc.Driver");
   Connection con= (Connection) DriverManager.getConnection("jdbc:mysql://localhost:3306/hrms","root","soft");

   Statement stmt=con.createStatement();

   boolean list1notSelected = jList1.isSelectionEmpty();     // caution or error whatever-> list1notSelected not in use
   boolean list2notSelected = jList2.isSelectionEmpty();     // same for list2notSelected
   boolean list3notSelected = jList3.isSelectionEmpty();     //same for list3notSelected
   boolean list4notSelected = jList4.isSelectionEmpty();     // same for list4notSelected

    String id;

    if ( list1notSelected = false){
         id  = (String) jList1.getSelectedValue();         // caution or error whetever
     }
   else if(list2notSelected = false){                           // every id in loop is not in use 
          id  = (String) jList2.getSelectedValue();
     }
   else if(list3notSelected = false){
          id  = (String) jList3.getSelectedValue();
     }
   else if(list4notSelected = false){
          id  = (String) jList3.getSelectedValue();
     }

     String sql1 = "Select * from emp where emp_id = '" + (id) + "'";  //error -> variable id might not have been initised
    ResultSet rs = stmt.executeQuery(sql1);
        while (rs.next())
    {
        String empid = rs.getString("emp_id");
        String f_name = rs.getString("first_name");
        String l_name = rs.getString("last_name");
        String qual = rs.getString("qualification");
        String dept = rs.getString("department");

        jTextField27.setText(""+ empid);
        jTextField28.setText(""+ f_name);
        jTextField29.setText(""+ l_name);
        jTextField30.setText(""+ qual);
        jTextField31.setText(""+ dept);

         }
}
catch(Exception e) {
    JOptionPane.showMessageDialog(this, e.getMessage());
}

Please Help . I have to submitt my project on monday and this is the only bug remaining.. Please.. Every part of software is working properly except this problem.

THANK YOU IN ADVANCE