title: How to send popup window messages/questions to clients during hubnet simulations (netlogo)
body: <p>I am quite new to Netlogo and I am currently programming a serious game with Hubnet. I was wondering if it is possible to send messages to specific clients via popups windows. I explain:
  For instance, if a client makes a certain decision (or action), he is alerted of its potential consequences by a message via a popup window. In other situations, I would like the popup window to be a "yes or no" or a multi-choice (with a popup menu) question, in which case I would like to store the client's answer in a specific variable (a global or a turtle variable).</p>
  
  <p>I know that is possible to send popup window messages to the user's interface with for instance:</p>
  
  <pre><code>user-one-of "value" [list-of-choices]
  
  user-message "value"
  
  user-yes-or-no? "value"
  </code></pre>
  
  <p>I really can't figure out how to do it for the client's interface, however I suspect that it is possible since in some situations, a client may receive a popup message after an action. For instance, when a client enters the wrong input type into an input box (e.g. a character instead of a number), an error message pops up like this:</p>
  
  <p><img src="https://i.stack.imgur.com/XaG1F.png" alt="error message popup in a client&#39;s interface"></p>
  
  <p>I'd like to program this kind of message by myself in the code so that such a message pops up following some client's actions (for instance when clicking inappropriately a button).</p>
  
  <p>Hope someone can help me on this one!</p>
  
  <p>Thanks!!</p>
  
  <p>Clément   </p>