problem with JTextfield..

hey there, i wrote this code for a form. its just GUI for now, but it won't display JTextfield.. :(


import javax.swing.*;
import java.awt.*;
import java.sql.*;
public class assignmnt {


public static void main(String[] args)
{
JFrame fr = new JFrame("Aup Student Database");
fr.setVisible(true);
fr.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
fr.setSize(500,500);
JPanel p = new JPanel(new GridBagLayout());
fr.getContentPane().add(p, BorderLayout.PAGE_START);

JLabel lb = new JLabel("Aup Student Database.");
p.add(lb);
JPanel p2= new JPanel(new GridBagLayout());
fr.add(p2);
fr.getContentPane().add(p2, BorderLayout.WEST);
GridBagConstraints c= new GridBagConstraints();
JLabel l1 = new JLabel("<---Search--->");
c.gridx=0;
c.gridy=10;
p2.add(l1,c);
JLabel l2=new JLabel("Student id: ");
c.gridx=0;
c.gridy=11;
p2.add(l2,c);
JButton b1=new JButton("Search");
c.gridx=10;
c.gridy=12;
p2.add(b1,c);
JTextField tf = new JTextField(20);
c.gridx=10;
c.gridy=11;
p2.add(tf,c);
}
}

Your JFrame should be set to visible at the end of the code not at the start. Move the setVisible(true) to the end of the main method.

Thanks! :)