Is it possible to add a method to the DOM document?

[gal007]

I am developing a function to find a particular element within another element identifier (similar to getElementById but that applies to any other element) ... Because this throws me arror:

var ancestor = document.getElementById('divAncestor');var child = ancestor.getElementById('divChild');

I know, HTML specifies that ids must be unique but reality proves that often running scripts that can have items with the same ids. So, thats the reason why I'm not simply calling the child like this:

var ancestor = document.getElementById('divChild');

The first option was to add this function to each HTML element, or at least the divs (because that's what interests me identify). The second, and is the one I prefer, is to add a method to the document object and call from there by passing the ID of the father and son as parameters. Is this possible?Thanks for your time.

Edited December 14, 2012 by gal007

[justsomeguy]

It's probably possible, but it's never required or a good idea to have multiple elements with the same ID. If you think you need that, then your design isn't good. You never need multiple elements with the same ID, there is always a way around that.