飘雪效果的swf

//第一帧动作
import flash.events.Event;

  for(var k:int=;k<;k++)
 {
   var xuehua:xue= new xue();
         xuehua.alpha = Math.random()+.;
            xuehua.height = xuehua.width = Math.random()*+;
         xuehua.x=Math.random()*;
      xuehua.y=Math.random()*;
         piaoxuekongjian.addChild(xuehua);
 }

addEventListener(Event.ENTER_FRAME,webcyz);

function webcyz(e:Event)
{
 for(var k:int;k<;k++)
 {
     var xuehua:xue= new xue();
     xuehua.alpha = Math.random()+.;
        xuehua.height = xuehua.width = Math.random()*+;
     xuehua.x=Math.random()*;
     piaoxuekongjian.addChild(xuehua);
 }
 //trace(piaoxuekongjian.numChildren);

  for(var i:int=;i<piaoxuekongjian.numChildren;i++)
  {

   var mc:xue = xue(piaoxuekongjian.getChildAt(i));

   if(mc.y>)
   {
   piaoxuekongjian.removeChild(mc);
   i--;
   }
   else
   {
     mc.y+=Math.random()*;
     mc.x+=(Math.random()-.)*;
   }

  }

}

//项目库中雪花的子类

package  {

 import flash.display.MovieClip;

 public class xue extends MovieClip {

  public function xue() {
   // constructor code
  }
 }

}

cs6源代码