I am sort of posting this question twice - my apologies.  I have done a bit more research and think I am on the right track but have hit a wall.  

I am trying to obtain the key of a new opportunity created by my sforce control..  The code I am using was initially posted by DevAngel and demonstrated how to calculate a field and perform an update using javascript and msxml.  I have modified the code to do clone operation from an existing opp.

The problem is that I can't seem to get to the id that is returned in the response from the create call per the API.  I can see the key when I display the msxml.responseText.   For some reason the selectNodes isn't working because objNodeList is undefined. 

Here is the code I am using to attempt to retrieve the "id" node that is returned per the API doc.  Any guidance would be greatly appreciated. 

if (status == 200)
{
  xmlDoc = new ActiveXObject("Msxml2.DOMDocument.3.0");
  xmlDoc.loadXML(msxml.responseText);
  xmlDoc.setProperty("SelectionNamespaces", "xmlns:sf='urn:sobject.enterprise.soap.sforce.com'");
  var objNodeList = xmlDoc.documentElement.selectNodes("//sf:id");
  var newoppid = objNodeList.item(0).text;
  document.write("<br><strong><center>Opportunity successfully cloned.");
  //window.parent.parent.location.href="https://na1.salesforce.com/" +  newoppid;