whats is "!function" purpose?
<blockquote>
  <p><strong>Possible Duplicate:</strong><br>
  <a href="http://stackoverflow.com/questions/3755606/what-does-the-exclamation-mark-do-before-the-function">What does the exclamation mark do before the function?</a>  </p>
</blockquote>



<p>I've seen this recently and can't figure it out:</p>

<pre><code>!function(){
   ...
}
</code></pre>

<p>what is the purpose of the <code>!</code> ("not" sign) before the function declaration?</p>
