function Ajax(){
	var swf_html = '<img src="http://static.chinaeasy.com/images/web/index/webloading.gif" border="0"/>';
	var tip = null;//放置提示用户等待的信息的对象。
	var disResponseObject = null;//显示服务器返回信息的对象。
	var callMethod = null; //服务器返回后，调用的方法。
	this.callServer = function(reqUrl,postStr,disResponseObj,callBack,flag,synchronize){
		disResponseObject = disResponseObj;
		callMethod = callBack;
		if(flag)
			setWaitInfo();
		service(reqUrl,postStr,synchronize);
	}
	var service = function(reqUrl,postStr,synchronize){
		var req = getRequest();
		req.onreadystatechange = function() {
			if (req.readyState == 4)
				handleResponse(req.responseXML, req.responseText);
		}
		var method = null==postStr? "get":"post";
		if(!synchronize) req.open(method,reqUrl,true);
		else req.open(method,reqUrl,false);
		if("post"==method){
			req.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
			req.setRequestHeader("Content-Length",postStr.length);	
			req.send(postStr);
		}
		try {
			req.send(null);
		} catch (e) {}
	}
	var handleResponse = function(xml,txt){
		if(null!=tip)//如果设置了提示用户等待信息，则在此取消。
			document.body.removeChild(tip)
		if(null!=disResponseObject)//如果放置返回信息的html对象存在，就将内容转入。
			disResponseObject.innerHTML = txt;
		if(null!=callMethod)//如果回调函数存在，则调用。
			callMethod(txt,xml);
	}
	var getRequest = function(){
		var req = null
		if (window.XMLHttpRequest) //for firefox etc..	
			req = new XMLHttpRequest();
		else if (window.ActiveXObject)//for IE
			req = new ActiveXObject("Microsoft.XMLHTTP");
		return req;	          	
	}
	var setWaitInfo = function(){
		tip = document.createElement("span");
		tip.innerHTML= swf_html+"在取得数据,请稍候 ........................";
		document.body.appendChild(tip);
		var style = "position:absolute;left:50%;top:250px;margin:0 0 0 -50px; display:block; padding:10px 20px; background:#E5E5E5; border:1px #999 solid;";
		Dom.setCss(tip,style);
	}
}
Ajax.doGet = function(reqUrl,disResponseObj,callBack,flag,synchronize){
	var ajax = new Ajax();
	var ur=reqUrl+(reqUrl.indexOf("?")>=0?"&t=":"?t=")+new Date();
	ajax.callServer(reqUrl,null,disResponseObj,callBack,flag,synchronize);
}
Ajax.doPost = function(reqUrl,postStr,disResponseObj,callBack,flag,synchronize){
	var ajax = new Ajax();
	ajax.callServer(reqUrl,postStr,disResponseObj,callBack,flag,synchronize);
}

var $id = function( id ){
	return document.getElementById(id);
}
var $name = function(name){
	return document.getElementsByName(name);
}
var $hidden=function(id){
	$id(id).style.display="none";
}
var $display=function(id){
	$id(id).style.display="block";
}
var $names = function(name){
	return document.getElementsByName(name);
}