I need to pull just the 'ObjectID' and all I get is a blank value, what am I doing wrong.   

here is the returned XML:

<soap:Envelope xmlns:soap=http://schemas.xmlsoap.org/soap/envelope/ xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/">

   <soap:Body xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">

      <AddFolderResponse xmlns="http://AgileWebservices">

         <AddFolderResult>

            <ObjectID>109614</ObjectID>

         </AddFolderResult>

      </AddFolderResponse>

   </soap:Body>

</soap:Envelope>

Here is my code:

global class docshare  
{  
  
   WebService static string invokeExternalWs(integer numOne, integer numTwo)  
    {  
        HttpRequest req = new HttpRequest();  
        req.setEndpoint('https://xxxxxxx');   // for security I have blanked this out
        req.setMethod('POST');  
        req.setHeader('Content-Type', 'text/xml; charset=utf-8');  
        req.setHeader('SOAPAction', 'http://AgileWebservices/AddFolder'); 
        string b = '<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:agil="http://AgileWebservices"><soapenv:Header/><soapenv:Body><agil:AddFolder><agil:user>lapispw</agil:user><agil:password>lapispw</agil:password><agil:folderName>Mikes fifth test</agil:folderName><agil:objectid>25953</agil:objectid></agil:AddFolder></soapenv:Body></soapenv:Envelope>';  
        req.setBody(b);  
        Http http = new Http();  
        try {  
          //Execute web service call here
          String xObjectID ='';  
          String soapNS = 'http://schemas.xmlsoap.org/soap/envelope/';     
          HTTPResponse res = http.send(req);
          Dom.Document doc = res.getBodyDocument();
          Dom.XMLNode root = doc.getRootElement();

          for(dom.XmlNode node : doc.getRootElement().getChildElements()) {
             xObjectID = node.getName();
             if(node.getName()== 'AddFolderResult') {
                xObjectID = node.getChildElement('ObjectID', soapNS).getText();
             }
          }
         return res.getBody();
       } catch(System.CalloutException e){  
          return 'ERROR:' + e;  
     }         
}  
}