阅读以下说明和JAVA 2代码，填入(n)处。

[说明]

以下程序实现了利用鼠标任意移动圆形的位置，仔细阅读代码和相关注释，将程序补充完整。

[代码6-1]

import java.awt.*;

import java.awt.event.*;

public class CIUSAMPLE extends Frame. implements MouseMotionListener, MouseListener

{

static CIUSAMPLE frm=new CIUSAMPLE ( );

int x=70,y=60,posX=70,posY=60,dx,dy;

public static void main (String args[])

{

frm.setTitle ("Dragging a circle");

frm.setSize (200,150);

(1)

ffm.addMouseMotionListener (frm);

frm.setVisible (true);

}

public void mousePressed (MouseEvent e)

{

(2)

dy=e.getY ( ) -posY;

}

public void mouseDragged (MouseEvent e)

{

(3)

y=e.getY ( ) -dy;

if(dx＞0&&dx＜50&&dy＞0&&dy＜50) //如果指针落在正方形区域内

{

Graphicsg=getGraphics ( );

(4)

}

}

public void paint (Graphics g)

{

g.setColor (Color.pink); //设置绘图颜色为粉红

g.fillOval(x,y,50,50); //以基准点为图形在左上角绘出圆形

(5)

posY=y；

}

public void mouseMoved (MouseEvent e) {}

public void mouseReleased (MouseEvent e) {}

public void mouseEntered (MouseEvent e) {}

public void mouseExited (MouseEvent e) {}

public void mouseClicked (MouseEvent e) {}

}