Document.prototype issue!

[carllucas]

I'm in the process of creating my own getElementsByCl assName function...

why does this not work in IE and it does on firefox?

Document.prototype.getElementsByClassName = function(para)
{
	alert(para);
}

the error i keep getting on IE (7) is:

object doesn't support this property

please help.

[mrhoo]

IE has never yet had a Document constructor.
No constructor, no prototype.

[acoder]

This works in Firefox, but not IE because Mozilla exposes all of the DOM constructors and IE doesn't. In any case, there is only ever one instance of Document, so there's no need to prototype it.