title: Supply Username and Password to witadmin
body: <p>Using <code>witadmin</code> I'm trying to delete a work item on a TFS in a <em>different domain</em>. I therefore use a login that is different from my Windows login, for which I'm asked when opening the web interface.</p>
  
  <p>However, <code>witadmin</code> fails with the following message, not prompting for username and password:</p>
  
  <blockquote>
    <p>Unable to destroy work item(s) 1. TF237090: Does not exist or access
    is denied.</p>
  </blockquote>
  
  <p>Is there a way to supply credentials as arguments or explicitly make <code>witadmin</code> prompt for credentials?</p>