var intervalId = null; 
function slideAd(id,nStayTime,he,sState){ 

	this.stayTime=nStayTime*1000 || 3000; 
	this.maxHeigth=he; 
	this.minHeigth=1; 
	this.state=sState || "down" ; 
	
	var obj = document.getElementById(id); 
	
	if(intervalId != null)
	window.clearInterval(intervalId); 
	
	function openBox(){ 
		var h = obj.offsetHeight; 
		obj.style.height = ( (this.state == "down") ? (h + 15) : (h - 15) )+"px"; 
		if(obj.offsetHeight>=this.maxHeigth){ 
			window.clearInterval(intervalId); 
			intervalId=window.setInterval(closeBox,this.stayTime); 
		} 
		if (obj.offsetHeight<=this.minHeigth){ 
			window.clearInterval(intervalId); 
			obj.style.display="none"; 
		} 
		//alert(obj.offsetHeight)
	} 
	function closeBox(){ 
		slideAd(id,this.stayTime,this.maxHeigth,"up"); 
		
	} 
	intervalId = window.setInterval(openBox,10); 
}