Changing the value of "this"
<p>I have this function :</p>

<pre><code>Number.prototype.f=function()
{
    this=2;//This is not working
}
var x=0;
x.f();
alert(a);//Here I want that x equal 2
</code></pre>

<p>And I want that x is 2 at the end!</p>
