<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">   
 <html xmlns="http://www.w3.org/1999/xhtml">   
   <head>   
      <meta http-equiv="Content-Type" content="text/html; charset=gbk" />   
      <style type="text/css">   
 #body{text-align:center;}    
 #test{width:119px;position:absolute;margin:10px auto;height:114px;background:url(http://www.blueidea.com/articleimg/2008/05/5766/01.jpg) ;border:2px dotted red;}    
      </style>   
      <script type="text/javascript"></script>   
   </head>   
   <body>   
         <div style='margin:10px 200px'>   
         <div><input type="button" value="~~~让我抖抖吧~~" onclick="nn.start()" /></div>   
         <div><input type="button" value="别抖了眼睛晕的很" onclick="nn.stop()" /></div>   
         <div id="test"></div>   
         </div>   
   </body>   
 </html>   
 <script type="text/javascript">   
  var m=document.getElementById("test");    
 function SKclass(obj,Rate,speed) {    
      var oL=obj.offsetLeft;    
      var oT=obj.offsetTop;    
      this.stop=null;    
      this.oTime=null;    
      this.state=0;    
      var om=this;    
      this.start=function(){    
         if(this.state==0){    
             ostart();    
             this.state=1;    
         }else{ 
             alert("这样你受得了吗？"); 
         }     
      }    
      var ostart=function(){    
              if(parseInt(obj.style.left)==oL-2){    
                 obj.style.top=oT+2+"px";    
                 setTimeout(function(){obj.style.left=oL+2+"px"},Rate)    
              }    
              else{    
                 obj.style.top=oT-2+"px";    
                 setTimeout(function(){obj.style.left=oL-2+"px"},Rate)    
             }    
         om.oTime=setTimeout(function(){ostart()},speed);    
      }    
      this.stop=function(){    
        clearTimeout(om.oTime);    
        this.state=0;    
          
      }    
 }    
 var nn=new SKclass(m,20,50);    
 </script>