How to show my button?

well, Im a newbie to java and im trying to make a calculator, but can any1 help me to show the button on the window, the application can run but no button were shown.. i wonder what code should i add..

Here is the code:

import javax.swing.*;

import java.awt.event.*;

import java.awt.*;

publicclass BCextends JFrame

{

JButton B1 =new JButton("1");

JButton B2 =new JButton("2");

JButton B3 =new JButton("3");

JButton B4 =new JButton("4");

JButton B5 =new JButton("5");

JButton B6 =new JButton("6");

JButton B7 =new JButton("7");

JButton B8 =new JButton("8");

JButton B9 =new JButton("9");

JButton B0 =new JButton("0");

JButton BPlus=new JButton("+");

JButton BMinus=new JButton("-");

JButton BDivide=new JButton("/");

JButton BMultiply =new JButton("*");

JButton BEqual=new JButton("=");

JButton BClear=new JButton("C");

JButton BBackspace=new JButton("Backspace");

JButton BSqrt=new JButton("sqrt");

JButton BPosMin=new JButton("+/-");

JButton BPoint=new JButton(".");

JPanel PButton=new JPanel();

Container contain;

public BC()

{

}

publicvoid ButtonConfiguration()

{

PButton.setLayout(new GridLayout(4,5,2,2));

PButton.add(B1);

}

publicstaticvoid main(String args[])

{

BC calculator=new BC();

calculator.setTitle("Butcher's Calculator");

calculator.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

calculator.setSize(300,350);

calculator.setResizable(false);

calculator.setVisible(true);

}

}

[3658 byte] By [w32sysfiea] at [2007-11-27 2:55:43]