function play(id,x,y,p) {
	
		var delta=1;
		
		var collection	= {};
		collection.object = document.getElementById(id);
		
		if('left'==p){
			collection.x = x;
		}else{
			collection.x= document.body.offsetWidth-x;
		}
		
		collection.y = y; 
		
		
		var followObj = collection.object ;
		var followObj_x	= (typeof(collection.x)=='string'?eval(collection.x):collection.x);		//??

		var followObj_y	= (typeof(collection.y)=='string'?eval(collection.y):collection.y);		//?
		var scroll_x = document.documentElement?document.documentElement.scrollLeft:document.body.scrollLeft;
		var scroll_y = document.documentElement?document.documentElement.scrollTop:document.body.scrollTop;

		if(followObj.offsetLeft!=(scroll_x+followObj_x)){
			var dx=(scroll_x+followObj_x-followObj.offsetLeft)*delta;
			dx=(dx>0?1:-1)*Math.ceil(Math.abs(dx));
			followObj.style.left=followObj.offsetLeft+dx+"px";
		}

		if(followObj.offsetTop!=(scroll_y+followObj_y)) {
			//alert(document.body.scrollTop);
			var dy=(scroll_y+followObj_y-followObj.offsetTop)*delta;
			dy=(dy>0?1:-1)*Math.ceil(Math.abs(dy));
			//window.status = dy;
			followObj.style.top=followObj.offsetTop+dy+"px";
		}
		
	}