onClipEvent(enterFrame)
{
     if(this.hitTest( root, xmouse, root, ymouse,true))
     {
         if(this, parent,nav 01,currentframe <this, parent,nav 01. totalframes>)
         {
             this. parent,nav 01.nextFrame();
             this. parent,son 01.play()
             this. parent,nav 01 select, gotoAndStop(2);
         }
这段代码是做什么的啊？