双击网页自动滚动JS代码

<script type="text/javascript">
  
  
var currentpos,timer; 
function initialize() 
{ 
timer=setInterval("scrollwindow()",1);
} 
function sc()
{
clearInterval(timer);
}
function scrollwindow() 
{
currentpos=document.body.scrollTop;
window.scroll(0,++currentpos);
if (currentpos != document.body.scrollTop) 
  sc();
} 
document.onmousedown=sc
document.ondblclick=initialize

  
  </script>