当按下鼠标时，一个圆不断地增大半径。
注意：请勿改动已有语句内容，仅在下划线处填入适当的语句。
import java.applet.*;
import java.awt.*;
import java.awt.event.*;
public class ex1 extends applet implements MouseListener

TextField text;
int x;
public void init()

x=6;
text=new TextField(30);
add(text);
addMouseListener(this);

public void paint(Graphics g)

x= x+2;
g.drawOval(10,10,x,x);

public void mousePressed(MouseEvent e)

Text.setText("鼠标按下的位置是："+e.getX()+","e.getY());
repaint();

public void mouseReleased(MouseEvent e)

Text.setText("鼠标松开的位置是："+e.getX()+","e.getY());
repaint();

public void mouseEntered(MouseEvent e)

Text.setText("鼠标进来的位置是："+e.getX()+","e.getY());
repaint();

public void mouseExited(MouseEvent e)

Text.setText("鼠标退出的位置是："+e.getX()+","e.getY());
______;