改正jAVA代码

package bag;

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

/*class Bag {

public double price;
public int interest;

}*/

public class Book_Get extends JFrame {

/**
*
*/
private static final long serialVersionUID = 1L;
JLabel L1;
JLabel L2;
JTextField T1;
JTextField T2;
JButton B1;
Container ContentPane, P1;

double price;
int interest;
static int MAX = 51;
int i, j, k = 1, m = 1, n;
int a[] = new int[MAX];
int ins[] = new int[MAX];
double total = 0;
int count = 0, pn, shu = 0, ma = 0;
double max = -1, sum;
int b[] = new int[MAX];

String output = "";

Book_Get info[] = new Book_Get[MAX];
public Book_Get() {

ContentPane = this.getContentPane();
ContentPane.setLayout(null);

L1 = new JLabel("输入所带钱数：");
L1.setBounds(10, 10, 160, 25);
ContentPane.add(L1);
L2 = new JLabel("输入书的种类：");
L2.setBounds(10, 45, 160, 25);
ContentPane.add(L2);
T1 = new JTextField();
T1.setBounds(100, 10, 120, 25);
ContentPane.add(T1);
T2 = new JTextField();
T2.setBounds(100, 45, 120, 25);
Conte