explain pattern of rebinding globals to locals in javascript
<blockquote>
  <p><strong>Possible Duplicate:</strong><br>
  <a href="http://stackoverflow.com/questions/2716069/how-does-this-javascript-jquery-syntax-work-function-window-undefined">How does this JavaScript/JQuery Syntax work: (function( window, undefined ) { })(window)?</a>  </p>
</blockquote>



<p>i see this pattern in the <a href="http://www.dustingetz.com/client-side-designer-templates/assets/javascripts/jquery-1.8.2.js" rel="nofollow">jquery source code (line 13)</a>, where they rebind 'window' and 'undefined' to locals:</p>

<pre><code>(function(window, undefined) {
     window.something = 42;
     var dummy = 42 === undefined;
}(window));
</code></pre>

<p>i think rebinding 'window' to a local is a strict mode thing (prevents accidental access to window) - but look at how they are binding <code>undefined</code> to a local as well. why?</p>
