String sql ="select Id,Username,Password,Division from Users where (username =? and password= ? and division=?)";

    try{
        int count = 0;
        pst = conn.prepareStatement(sql);

        pst.setString(1, txt_username.getText());
        pst.setString(2, txt_password.getText());
        pst.setString(3, txt_combo.getSelectedItem().toString());

        rs = pst.executeQuery();
       while (rs.next()){
           int Username =rs.getInt(1);
           Emp.empnum = Username;
           String username = rs.getString("username");
           Emp.empname = username;
           count = count+1;
       }

        String access = (txt_combo.getSelectedItem().toString());

        if(access =="Administrator,Admin,User"){
            if(count == 1){
                JOptionPane.showMessageDialog(null, "Success");
                MainMenu j = new MainMenu();
                j.setVisible(true);
                this.dispose();
            }else {
                JOptionPane.showMessageDialog(null, "The Username or Password you entered was incorrect!");
            }
        }

    }catch (Exception e){

    JOptionPane.showMessageDialog(null, e);

    }
    finally {

        try{
            rs.close();
            pst.close();

        }catch (Exception e){
    }
    }
}`