/**
* Ajax对象
*    function functionName(reAjax,status){if(status == 200)alert(reAjax.responseText);}
*

function LoginRes(reAjax,status)
{
    if(status == 200)
    {
        var res=reAjax.responseText;
        //alert(res);//res 为返回的结果
        document.getElementById("err_txt_LoginId").innerHTML=" "+res;
    }
}
 function ajax(url)
 { 
     var myAjax=new Ajax();
     //myAjax.open("../xx/xx.aspx?xx=xx" ,LoginRes);
     myAjax.open(url ,LoginRes);
     myAjax.send();
 }
 
* 例：1:GET
*    var myAjax=new Ajax();
*    myAjax.open("http://www.ttzx.com:88/ajax/re.php",functionName);
*    myAjax.send();
*
* 例：2:POST
*   var myAjax=new Ajax(); 
*   myAjax.open("http://www.ttzx.com:88/ajax/re.php",functionName);
*   myAjax.send("sendType=Post&sendValue=myDatas");
*/
function Ajax(){
/**
* 初始化一个xmlhttp对象
*/	this.newAjax=function(){
	    var name=false;
	    try{ 
	    　　 name = new ActiveXObject("Msxml2.XMLHTTP"); 
	    　 } catch (e) { 
	    　 　 try { 
　	    　　       name = new ActiveXObject("Microsoft.XMLHTTP"); 
	    　　  } catch (e) { 
　	              if (typeof XMLHttpRequest!='undefined') { 
　	    　           try { 
　	    　                name = new XMLHttpRequest(); 
 	                 } catch (e) {
	                     if (window.createRequest){
		                    try{
		                        name=window.createRequest();
		                    } catch (e) {
								alert('创建XMLHTTP对象失败！');
		    	                name=null;
		                    }
                         }
	    　            } 
    	    　 　  } 
　	           }
		   }
	  return name;
	}
	var backthis=this;//备份Ajax对象实例 
	this.call=function() { 
	 	 	  //如果执行是状态正常，那么就把返回的内容赋值给上面指定的层
	 	 	  if (backthis.Ajax.readyState == 4){ 
				backthis.setReFunction(backthis.Ajax,backthis.Ajax.status);
			  }
	}
/**
* xmlhttp对象的send方法
*/    this.send=function(value){
		if (typeof(this.url) == 'undefined'){
		  return false;
	    }
　      if (typeof(this.call) == 'undefined'){
		  return false;
	    }
        if(typeof(value)=='undefined'){//使用Get方式进行请求
	      if(typeof(this.userName) =='undefined') 
	        this.Ajax.open("GET",this.url,this.varAsync);
	      else
	        this.Ajax.open("GET",this.url,this.varAsync,this.userName,this.passWord);
	      this.Ajax.onreadystatechange = this.call;//设置执行状态回调处理函数句柄
          this.Ajax.send(null);//发送
	    }
	    else{ //使用POST方式进行请求
	      if(typeof(this.userName) =='undefined') 
	        this.Ajax.open("POST",this.url,this.varAsync);
	      else
	        this.Ajax.open("POST",this.url,this.varAsync,this.userName,this.passWord);
	      this.Ajax.onreadystatechange = this.call;//设置执行状态回调处理函数句柄
 	      this.Ajax.setRequestHeader("Content-Length",value.length);   
          this.Ajax.setRequestHeader("Content-type","application/x-www-form-urlencoded"); 
          this.Ajax.send(value);//发送
	    }
	}
/**
* AJAX对象的OPEN方法:取消发送
*/  this.open=function(url,reFunction){
			  if (typeof(url) == 'undefined'){
		         return false;
	          }
	          this.url=url;
			  if (typeof(reFunction) != 'undefined'){
		         this.setReFunction= reFunction;
	          }
    }
/**
* xmlhttp对象的resend方法:取消发送
*/	this.close=function(){
	           this.Ajax.abort();
    }
/**
* xmlhttp对象的newXmlDom方法:创建XmlDom对象
*/	this.newXmlDom=function(){   
      try{   
		  return   backthis.Ajax.responseXML;;   
	  }catch(e){ 
		  return   null;
	  }   
	} 
	this.userName;      //如果服务器需要验证,此处指定用户名.
	this.passWord;      //验证信息中的密码部分.
	this.url;           //请求的URL地址,可以为绝对地址也可以为相对地址.
	this.varAsync=true; //布尔型,指定此请求是否为异步方式,默认为true.
	this.setReFunction=function(reAjax,status){alert(status)}; //操作成功后要调用的用户自定义函数.
	this.Ajax=this.newAjax();
}