title: rules for "prevent this page from creating additional dialogs"
body: <p>I try to understand Firefox's behavior regarding the added "prevent this page from creating additional dialogs" on dialog boxes.</p>
  
  <p>Using jquery, if I add the following listeners :</p>
  
  <pre><code>//html
  &lt;input class="testInput" /&gt;
  
  //javascript
  $('.testInput')
  .click(function(){ alert('clicked') })
  .keyup(function(){ alert('keyup') })
  </code></pre>
  
  <ol>
  <li>When clicking on the input, the alert box appears normally, until the
  ~13th time.</li>
  <li>When hitting a key, on the other hand, the second message box already
  appears with the message "prevent this page from creating additional
  dialogs". Actually, there seems to be some tiemout, and if I wait
  like 2 seconds between two keystrokes, the message disappears.</li>
  </ol>
  
  <p>From my informal tests, <code>2.</code> actually applies whenever the alert box is not called from within a onclick callback (e.g : keyup callback, displaying an alert box in answer to an ajax action...)</p>
  
  <p>I am using Firefox 9.0.1 under Ubuntu, as far as I know I haven't tweaked firefox's settings regarding these thresholds.
  I imagine it happens with any recent version of any browser.</p>
  
  <p>I am using the jQuery library, but I don't think it is relevant here.</p>
  
  <p>My question is :
  What are the exact rules which make this warning appear in a dialog box ?</p>
  
  <p>[Edit]</p>
  
  <p>Using Chromium/Ubuntu (version 17.0.963.26), the threshold seems to be only the delay between two dialog boxes.</p>
  
  <p>You can test this from jsfiddle <a href="http://jsfiddle.net/RoryMcCrossan/9XwTn" rel="noreferrer">here</a> (thx Rory McCrossan)</p>