js双击鼠标滚动屏幕的代码

//双击鼠标滚动屏幕的代码
	var currentpos,timer;
	function initialize()
	{
	timer=setInterval ("scrollwindow ()",30);
	}
	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