//选择器
function $a(id,tag)
{
	var re=(id&&typeof id!="string")?id:document.getElementById(id);
	if(!tag)
	{
		return re;
	}
	else
	{
		return re.getElementsByTagName(tag);
	}
}
//首页下拉菜单
function ShowList(id,vas)
{
	var zj=$a(id), mb=$a(id,"dt")[0],xs=$a(id,"dd")[0],sj=$a(xs,"li");if(vas!=null){var va=$a(vas);}
	mb.onclick=function(){xs.className="show";};
	zj.onmouseout=function(){xs.className="";};
	xs.onmouseover=function(){xs.className="show";};
	xs.onclick=function(){xs.className="";}
	for(var i=0;i<sj.length;i++){reg(i);}
	function reg(i)
	{
		sj[i]["onmouseover"]=function(){sj[i].className="show";if(vas){va.value=mb.innerHTML= sj[i].innerHTML;}else{mb.innerHTML=$a(sj[i],"a")[0].innerHTML;}}
		sj[i]["onmouseout"]=function(){sj[i].className="";};
	}
}