private void button3MouseClicked(java.awt.event.MouseEvent evt) {//GEN-FIRST:event_button3MouseClicked
if(numberofpins < 4)
{
    if(numberofpins == 0)
    {
        Login_form.setString1("2");
    }
    if(numberofpins == 1)
    {
        Login_form.setString2("2");
    }
    if(numberofpins == 2)
    {
        Login_form.setString3("2");
    }
    if(numberofpins == 3)
    {
        Login_form.setString4("2");
    }
    numberofpins +=1;
    jLabel2.setText(Integer.toString(numberofpins));
}
    else
{
    System.out.print(Timetable_main_RWRAF.checkDelete());           
                 JOptionPane.showMessageDialog(null,"You've already entered your 4 digit pin!", "Timetable Management Program", JOptionPane.INFORMATION_MESSAGE);
      
}// TODO add your handling code here:
}//GEN-LAST:event_button3MouseClicked