function InitAjax(){
	var ajax=false; 
	try { 
		ajax = new ActiveXObject("Msxml2.XMLHTTP"); 
	} catch (e) { 
		try { 
			ajax = new ActiveXObject("Microsoft.XMLHTTP"); 
		} catch (E) { 
			ajax = false; 
		} 
	} 
	if (!ajax && typeof XMLHttpRequest!='undefined') { 
		ajax = new XMLHttpRequest(); 
	} 
	return ajax; 
}
function getUserName(u,n){
	if(typeof(u)=='undefined'){
		return false;
	}
	//需要进行Ajax的URL地址 
	var url=u;
	//获取新闻显示层的位置 
	var show=document.getElementById(n);
	//实例化Ajax对象
	var ajax=InitAjax();
	ajax.open('GET',url,true);
		
	ajax.onreadystatechange = function(){
		if (ajax.readyState == 4 && ajax.status == 200) { 
			show.innerHTML = ajax.responseText; 
			return true;
		}
	}
	ajax.send(null); 
}