java计算器代码的问题,谢谢各位高手,脑袋快想破了~

怎么才能让下面的程序正常运行出来,现在只能显示出main()中的语句.请帮帮我,谢谢各位高手..~~(中间部分略去)
public class Calculator extends JFrame {
GridLayout gl1,gl2,gl3;
Panel p0,p1,p2,p3;
JTextField tf1;
TextField tf2;
Button b0,b1,b2,b3,b4,b5,b6,b7,b8,b9,b10,b11,b12,b13,b14,b15,b16,
b17,b18,b19,b20,b21,b22,b23,b24,b25,b26;
StringBuffer str;
double x,y;
int z;
static double m;

public Calculator()
{

gl1=new GridLayout(1,4,10,0);
gl2=new GridLayout(4,1,0,15);
gl3=new GridLayout(4,5,10,15);

tf1=new JTextField(27);
tf1.setHorizontalAlignment(JTextField.RIGHT);
tf1.setEnabled(false);
tf1.setText("0");
tf2=new TextField(10);
tf2.setEditable(false);

b0=new Button("Backspace");

b0.addActionListener(new Bt());
b1=new Button("CE");

我以前做过的给你参考一下吧

import java.awt.*;
import javax.swing.*;
import java.awt.event.*;

public class CalculatorFrame extends JPanel implements ActionListener {

protected JTextField txtResult = new JTextField();
protected String[] btnames = {"7", "8", "9", "/", "4", "5", "6", "*",
"1", "2", "3", "-", "0", "C", "=", "+"};
boolean flag = false;
String action;
double operand1, operand2;
double result;

protected CalculatorFrame() {

/*底层Panel的布局*/
this.setLayout(new BorderLayout());

/*设置TextField右对齐*/
txtResult.setHorizontalAlignment(JTextField.RIGHT);

/*设置btnPanel为四列*/
JPanel btnPanel = new JPanel();