js调用WebService运行的问题

Uncaught InvalidStateError: Failed to execute 'send' on 'XMLHttpRequest': The object's state must be OPENED.

http://www.cnblogs.com/manyiString/archive/2012/05/24/js4.html

楼主是如何调用的 可以贴代码出来看一下么

这是WebService.js

    var WSDLS = {};  

var WebService = new Class({  

    url : '',  
    method : '',  
    options:   
    {  
        method:'GET',  
        data: null,  
        update: null,  
        onComplete: Class.empty,  
        onError:Class.empty,  
        evalScripts: false,  
        evalResponse: false  
    },  

    initialize: function(url,method,options)  
    {  
        this.url = url;  
        this.method = method;  
        this.options = options;  

    },  

    request : function()  
    {  
        var wsdl = WSDLS[this.url];  
        if(!wsdl)   
        {  
            var op = {method:'GET',async: false};  
            var wsdlAjax = new XHR(op).send(this.url + "?wsdl", null);            
            wsdl = wsdlAjax.transport.responseXML;  
            WSDLS[this.url] = wsdl;  
        }  
        this.setSoap(wsdl);  
    },  

    setSoap : function(wsdl)  
    {  

        var ns = (wsdl.documentElement.attributes["targetNamespace"] + "" == "undefined") ? wsdl.documentElement.attributes.getNamedItem("targetNamespace").nodeValue : wsdl.documentElement.attributes["targetNamespace"].value;  
        var sr =   
                "<?xml version=\"1.0\" encoding=\"utf-8\"?>" +  
                "<soap:Envelope " +  
                "xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" " +  
                "xmlns:xsd=\"http://www.w3.org/2001/XMLSchema\" " +  
                "xmlns:soap=\"http://schemas.xmlsoap.org/soap/envelope/\">" +  
                "<soap:Body>" +  
                "<" + this.method + " xmlns=\"" + ns + "\">" +  
                     (this.options.data === null ?"":this.options.data) +  
                "</" + this.method + "></soap:Body></soap:Envelope>";  

        this.options.method = 'post';  
        this.options.data = null;  

        var soapaction = ((ns.lastIndexOf("/") != ns.length - 1) ? ns + "/" : ns) + this.method;  

        var soapAjax = new Ajax(this.url,this.options);  
        soapAjax.setHeader("SOAPAction", soapaction);  
        soapAjax.setHeader("Content-type", "text/xml; charset=utf-8");  
        soapAjax.request(sr);  
    }  

});  

var soapAjax = new Ajax(this.url,this.options);