function menuHover(elementId,tagName){
	var element=document.getElementById(elementId);
	if(!element)return false;
	var items=element.getElementsByTagName('li');
	var subItem;
	for(var i=0;i<items.length;i++){
		items[i].onmouseover=function(){
			this.className='hover';
			subItem=this.getElementsByTagName(tagName)[0];
			if (!subItem) return false;
			subItem.className='show';
		}
		items[i].onmouseout=function(){
			this.className='';
			subItem=this.getElementsByTagName(tagName)[0];
			if (!subItem) return false;
			subItem.className='';
		}
	}
}