Grid layout frames GUI

[fritz1474]

I am having a problem with creating a calculator. I using JFrames to create a non working calculator that has the text box and the number grid, but the numbers are not coming into the frame. If I remove the text box lines, the numbers are shown. Any help is appreciated...

Here is the code:

[hardwired]

import java.awt.BorderLayout;
import java.awt.GridLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;

public class GLF extends JFrame
{
    private JTextField textField1;
    private JButton[] buttons;
    private final String[] names =
    {
        "7", "8", "9", "/", "4", "5", "6",
        "*","1","2","3","-","0",".","=","+"
    };

    public GLF()
    {
        super( "Calculator" );
        System.out.println("default layout manager for JFrame = " +
                            getLayout().getClass().getName());
        textField1 = new JTextField( 10 );

        textField1.setHorizontalAlignment(JTextField.RIGHT );
        // same as getContentPane().add(textField1,...
        add( textField1,BorderLayout.NORTH );

        JPanel center = new JPanel( new GridLayout(4,4,1,1) );
        buttons = new JButton[ names.length ]; // create array of JButtons

        for ( int count = 0; count < names.length; count++ )
        {
            buttons[ count ] = new JButton( names[ count ] );
            //buttons[ count ].addActionListener( this );
            center.add( buttons[count]);
        }
        add(center, BorderLayout.CENTER);
        pack();
        setVisible(true);
    }

    public static void main(String[] args)
    {
        new GLF();
    }
}