ActiveXObject.Save()方法给出权限拒绝错误

    function getfun(a)
    {
      var xmlObj = new ActiveXObject("Msxml2.DOMDocument");
            var sXml  = "<?xml version='"1.0'" ?>" ;
                  sXml += "<soap:Envelope "
                  sXml += "xmlns:xsi='"http://www.w3.org/2001/XMLSchema-instance'" " ;
                  sXml += "xmlns:xsd='"http://www.w3.org/2001/XMLSchema'" " ;
                  sXml += "xmlns:soap='"http://schemas.xmlsoap.org/soap/envelope/'">" ;
                  sXml += "<soap:Body>" ;
                  sXml += "<Add xmlns='"http://tempuri.org/'">" ;
                  sXml = sXml + "<a>" + a.value  + "</a>" ;
                  sXml += "</Add></soap:Body></soap:Envelope>"
   // Try to parse the XML string into DOM object 
            xmlObj.loadXML(sXml) ;
            var xmlHTTP = new ActiveXObject("Msxml2.XMLHTTP") ;
            xmlHTTP.Open ( "Post", "http://localhost/MyWebVirtual/MyWebService.asmx", false) ;
            xmlHTTP.setRequestHeader("SOAPAction", "http://tempuri.org/Add") ;
            xmlHTTP.setRequestHeader("Content-Type", "text/xml; charset=utf-8" ) ;
            xmlHTTP.Send(xmlObj.xml) ;
            var xmlResponse = xmlHTTP.responseXML ;
            answer.innerText = xmlResponse.selectSingleNode("soap:Envelope/soap:Body/AddResponse/AddResult").text ;
            var xmlObj2 = new ActiveXObject("Microsoft.XMLDOM");
            xmlObj2.resolveExternals = true;
            xmlObj2.preserveWhiteSpace = true;
            xmlObj2.validateOnParse = false;
            xmlObj2.async = false;
            xmlObj2.loadXML(xmlResponse.selectSingleNode("soap:Envelope/soap:Body/AddResponse/AddResult").text);
            xmlObj2.save("C:''Users1.xml");
 }

我得到一个错误，而保存xmlObj2到一个文件。