Where is arguments property defined?
<p>Consider the following code</p>

<pre><code>function add(x, y) {
    alert(arguments.length);
    var total = x + y;
    return total;
}
add();  // NaN alerts 0
add(2,3);  // 5 alerts 2
add(3,3,5);  //6 alerts 3
</code></pre>

<p>Where is arguments defined? How come it is available inside my add function?</p>
