How come alert breaks javascript execution?
<p>how is that possible that call to the alert function changes behavior of a js script? Something like that:</p>

<pre><code>function add_token (item) {
    var li_data = $.data(item.get(0), "tokeninput");
</code></pre>

<p>works but this:</p>

<pre><code>function add_token (item) {
    alert('a');
    var li_data = $.data(item.get(0), "tokeninput");
</code></pre>

<p>doesn't - I get following error in firebug: li_data is undefined jquery.tokeninput.js Line 336 (adding alert call is the only change)</p>

<p>(as you can see I'm playing with Tokenizing Autocomplete jQuery plugin - <a href="http://loopj.com/2009/04/25/jquery-plugin-tokenizing-autocomplete-text-entry/" rel="nofollow">http://loopj.com/2009/04/25/jquery-plugin-tokenizing-autocomplete-text-entry/</a> )</p>

<p>Now that's something that bugs me. Can someone explain to me how is that even possible? </p>

<p>UPDATE: I tried using Chrome instead of Firefox and this particular problem doesn't appear. So now what? It should be considered some kind of a bug in FF or is there something else about this that I'm not aware of?</p>
