Access a SOAP Web service using XMLhttprequest

Access a SOAP Web service using XMLhttprequest

Hello,
I am new to JS and jquery. I want to access a SOAP web service to access GPS information of our commuter buses. I am able to do so using a .Net program on the sever side but I want to do the same on the client side.

I want to access the Web service using XMLhttprequest and plot the data on a map.  I followed an article( http://openlandscape.net/2009/09/25/call-soap-xm-web-services-with-jquery-ajax/#comment-478) and wrote my code but it is giving an 'undefined error' 

I am not sure where I am going wrong.
Would all SOAP web service respond to Jquery? or is the issue with my code.



<html>
  <head>
    <title>SOAP JavaScript Client Test</title>
  </head>
  <body>
    <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.8.3/jquery.min.js"></script>
    <script type="text/javascript">
    function OnSuccess(data, status) {
        alert(data.d);
    }
$(document).ready(function() {
        jQuery.support.cors = true;
    });
function OnError(request, status, error)
    {
        alert(error.responseText + " " + status);
    }

    function signOn() {
      // build SOAP request
      var acct = ####;
      var user = '#####';
      var webServiceURL = 'http://wd.air-trak.com/ATAuthenticationWS/service.asmx?op=GetKey';
      var soapMessage = '<soap12:Envelope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xmlns:xsd="http://www.w3.org/2001/XMLSchema"'
+' xmlns:soap12="http://www.w3.org/2003/05/soap-envelope"'
+'  <soap12:Body>'
+'   <GetKey xmlns="http://www.air-trak.com/API/ATAuthenticationWS/"'
+'      <pAccount>' + acct+ '</pAccount>'
+'     <pUser>' +user+ '</pUser>'
+'    </GetKey>'
+'  </soap12:Body>'
+'</soap12:Envelope>';;
      $.ajax({
        url: webServiceURL,
        type: "POST",
        dataType: "xml",
        data: soapMessage,
        processData: false,
        contentType: "text/xml; charset=\"utf-8\"",
        success: OnSuccess,
        error: OnError
      });
    }
    </script>
    <form name="Demo" action="" method="post">
      <div>
        <input type="button" value="test" onclick="signOn();" />
      </div>
    </form>
  </body>
<html>