function ScrollChaser(id,int)
{
	var el;
	var initTop;
	var interval = int;
	//
	function setting()
	{
		el = document.getElementById(id);
		el.style.position = 'absolute';
		initTop = el.offsetTop;
		//
		try {
			window.addEventListener('scroll', scrollEvent, false);
		} catch (e) {
			window.attachEvent('onscroll',scrollEvent);
		}
	}
	function scrollEvent()
	{
		var myInt = setInterval(function()
			{
				var cur = (document.body.scrollTop||document.documentElement.scrollTop)+1;
				var myTop = el.offsetTop;
				var d = cur-myTop;
				if(Math.abs(d)>1) {
					if( cur >= initTop )
					{
						var y = myTop + d/3;
						el.style.top = y+"px";
					} else {
						el.style.top = initTop+"px";
						clearInterval(myInt);
					}
				} else {
					el.style.top = cur+"px";
					clearInterval(myInt);
				}
			},interval);
	}
	try {
		window.addEventListener('load', setting, false);
	} catch (e) {
		window.attachEvent('onload', setting);
	}
}
//
if(document.getElementById("sideMenu"))
	var sc = new ScrollChaser('sideMenu',100);