Why canvas doen't work with jQuery selector?
===

I have made simple example of using canvas and then I saw that my code doesn't work when I use jQuery selector.

**Examples:**

[Javascript][1]

[JQuery][2]

So I have no idea why it happened. Is there any limitations about it?


  [1]: http://jsfiddle.net/cXXdP/4/
  [2]: http://jsfiddle.net/46VKa/2/