//Ë«»÷¹öÆÁ£¬µ¥»÷Í£Ö¹µÄ´úÂë
  var currentpos,timer;

  function scrollwindow(){ 
    currentpos=document.body.scrollTop;
    window.scroll(0,++currentpos); 
    if (currentpos != document.body.scrollTop)
      stop();
  }

  function initialize(){ 
    timer=setInterval("scrollwindow()",10);
  } 

  function stop(){
    clearInterval(timer);	
  }

  document.ondblclick=initialize;
  document.onmousedown=stop;