title: How to pop a tkMessageBox in a twisted powered server
body: <p>I have a server based on twisted reactor, and I need the following scenario:
  the server can receive two types of request</p>
  
  <ul>
  <li>ADD(x,y) and returns a sum</li>
  <li>HUMAN_PERMISSION which returns true only if the human user approved the ip of the client</li>
  </ul>
  
  <p>I am using tkMessageBox to ask the human user, but the problem is that it blocks the whole reactor and the server becomes unresponsive to other requests</p>
  
  <p>I understand that I have to use twisted's deferred here in some way, just dont know how
  this: doesnt seem to work, it still blocks the whole reactor</p>
  
  <pre><code>d = deferLater(reactor, 1,tkMessageBox.showinfo, "is he ok?", clientIp)
  d.addCallback(confirmUser)
  </code></pre>