//双击滚屏，单击停止
var currentpos,timer;                                
var UpOrDown; //为真时向上移,为假时向下移 ,默认值为真                             
UpOrDown=true;  
                           
function Initialize()                                
{                                
  timer=setInterval("ScrollWindow()",8);                               
}                                
function ScFun()            
{                               
  clearInterval(timer);	                               
}      
                         
function ScrollWindow()                                
{                                
  currentpos=document.body.scrollTop;                                
  if (UpOrDown)   
	window.scroll(0,++currentpos);                                
  else                             
	window.scroll(0,--currentpos);                                                      
  if (currentpos != document.body.scrollTop)           
  {   
       ScFun();       
       UpOrDown=!(UpOrDown);                           
  }//end if                     
}                                
document.onmousedown=ScFun                               
document.ondblclick=Initialize