大家帮我看看这个AJAX怎么用啊,摸了半天不知道怎么用

function Ajax(sUrl,sRecvType,sQueryString,oResultFunc,sError,sState,sDownloadEnd) 

{

    //访问服务器地址

    this.sUrl = sUrl;    

    //this.object = null;

    //this.sMethod = null;

    //返回数据类型,0为xml，1为text

    this.sRecvType = sRecvType;

    // 错误字符串

    this.ErrorStr = null;

    // 错误事件驱动,当发生错误时触发

    this.OnError = null;

    // 状态事件驱动,当状态改变时触发

    //this.EventState = EventState;

    

    this.sRecvType = sRecvType;

    

    this.QueryString = sQueryString;

    

    this.oResultFunc = oResultFunc;

	//页面上显示错误的html标记id,标记不填或留空则采用默认标记，下同

	this.sError = sError;

	//页面上显示状态的html标记id

	this.sState = sState;

	//页面上显示完成回调的html标记id

	this.sDownloadEnd = sDownloadEnd;

    //建立xmlhttp对象

    this.XmlHttp = this.createXMLHttpRequest();    

    

    XmlHttp = this.XmlHttp;



    

    if (this.XmlHttp == null) {

        alert('XMLHTTPREQUEST对象创建不成功!');

    } else if (typeof this.XmlHttp == "object") {

        //alert('XMLHTTPREQUEST对象创建成功!');

    }

    

    Obj = this;

    //定义xmlhttp对象的状态句柄

    this.XmlHttp.onreadystatechange = this.handler;

    

};



/*

创建XMLHttp对象

*/

Ajax.prototype.createXMLHttpRequest = function() {

    if (window.XMLHttpRequest){     

        return  new XMLHttpRequest();

    } else {      

        var MSXML = ["MSXML2.XMLHTTP.6.0", "MSXML2.XMLHTTP.5.0", "MSXML2.XMLHTTP.4.0", "MSXML2.XMLHTTP.3.0", "MSXML2.XMLHTTP", "Microsoft.XMLHTTP"]; 

        for(var n = 0; n < MSXML.length; n ++) {

            try {

              return new ActiveXObject(MSXML[n]); return; 

            } catch(e) {

                this.ErrorStr = "XMLHttpRequest对象创建不成功!.";

            } 

        }

    }

    this.ErrorStr = "你的浏览器不支持XMLHttpRequest对象.";    

    if (typeof this.EventError == "function") {

         this.EventError(this.ErrorStr); 

    }    

    return null;

};



/*

发送服务器请求

*/

Ajax.prototype.send = function() {

    sUrl = this.sUrl;

    sMethod = this.sMethod;

    var sUrl = sUrl + "?timeStamp=" + new Date().getTime();//采取当前时间取不同url，防止页面缓存

	

    var queryString = this.QueryString;

    if (sMethod.toLocaleUpperCase() == 'POST') {

        //POST方式

        this.XmlHttp.open("POST",sUrl,true);

        this.XmlHttp.setRequestHeader("content-length",queryString.length);

        //this.XmlHttp.setRequestHeader("Content-Type","application/x-www-form-urlencoded","charset=UTF-8");

        this.XmlHttp.send(queryString);

    } else if (sMethod.toLocaleUpperCase() == 'GET') {

	    //GET方式

        queryString = sUrl + "&" + this.QueryString;

        this.XmlHttp.open("GET",queryString,true);

    this.XmlHttp.send(null);        

    }

};



/*

sRecvType 接受数据类型:0为xml 1为text

responseBody  将回应信息正文以unsigned byte数组形式返回的未经解码的二进制数据.只读 

responseText 将响应信息作为字符串返回.只读

*/



Ajax.prototype.handler = function () {

	

    if(Obj.EventState) 

	{

      Obj.EventState(XmlHttp.readyState);

	  

    }

  if (XmlHttp.readyState == 4) 

  {

      if (XmlHttp.status == 200) 

	  {          

          if(Obj.oResultFunc)

		  {

              this.RetData = Obj.UTFTOGB(XmlHttp.responseBody);

              //alert(this.RetData);//返回ajax请求的内容

			  //此处可以添加详细的处理函数，使用ajax返回结果，做相应操作

              //Obj.oResultFunc(this.RetData); 

          } 



/*

sRecvType 接受数据类型:1为text 0为xml 

*/

    

          Result = (Obj.sRecvType) ? XmlHttp.responseText :    Result = XmlHttp.responseXML;

          Obj.EventDownloadEnd(Result);          

          Obj.status = XmlHttp.status;

	 }

	 else 

	 {

		

          Obj.ErrorStr = "您所请求的页面有异常。";

          if (typeof Obj.EventError == "function") {

              Obj.EventError(Obj.ErrorStr); 

      }

    }

  }

};





// UTF 转入 GB (by:Rimifon) 

Ajax.prototype.UTFTOGB = function(strBody) { 

    var Rec=new ActiveXObject("ADODB.RecordSet"); 

    Rec.Fields.Append("DDD",201,1); 

    Rec.Open(); 

    Rec.AddNew(); 

    Rec(0).AppendChunk(strBody); 

    Rec.Update(); 

    var HTML=Rec(0).Value; 

    Rec.Close(); 

    delete Rec; 

    return(HTML); 

};





// 错误回调事件函数 

Ajax.prototype.EventError = function(strValue){ 

    if(this.sError != null && this.sError != "" && document.getElementById(this.sError) != "undefined"){

    document.getElementById(this.sError).innerHTML = strValue; 

	}

};



// 状态回调事件函数 

Ajax.prototype.EventState = function(strValue) { 

    var strState = new Array(); 

    strState[0] = "未初始化..."; 

    strState[1] = "开始读取数据..."; 

    strState[2] = "读取数据...";

    strState[3] = "读取数据中..."; 

    strState[4] = "";//"读取完成...";

    statusText = (strValue < 4 || strValue != 0) ? strState[strValue] : strState[0];

	if(this.sState != null && this.sState != "" && document.getElementById(this.sState) != "undefined"){

    document.getElementById(this.sState).innerHTML = "<img src='images/loading.gif'> <font color=red>" + statusText + "</font> "; 

	}

};



// 完成回调事件函数 

Ajax.prototype.EventDownloadEnd = function (strValue) 

{

    if(this.sDownloadEnd != null && this.sDownloadEnd != "" && document.getElementById(this.sDownloadEnd) != "undefined")

	{

		document.getElementById(this.sDownloadEnd).innerHTML = strValue; 

	}

};  

以上这个怎么用呢
var proname = $("stu_pro").value;
var aj = new Ajax("adminajax.php",1,"menu=setcity&proid="+proname,'',"myajax","myajax","myajax");
aj.sMethod = "get";
aj.send();

这样用,只能把adminajax.php?menu=setcity&proid=..这个地址得到的值传到了页面上的一个ID为myajax的 DIV里面
可是我想得到这个值,没办法得到它
我再用
var mytext = $("myajax").value;
alert(mytext);
得到的缺是开始加载的"<img src='images/loading.gif'> <font color=red>" + statusText + "</font> ";

我如果把
var aj = new Ajax("adminajax.php",1,"menu=setcity&proid="+proname,'',"myajax","myajax","myajax");
改成了
var aj = new Ajax("adminajax.php",1,"menu=setcity&proid="+proname,getvalue(),"myajax","myajax","myajax");
再在getvalue()函数里来取myajax.innerHTML
发现他是先执行getvalue();再加载AJAX,而不是AJAX执行好了,再取innerHTML,高手帮我看看吧