[jQuery] Work on one specific node and not on the window.document

[tij_dev]

Hi guys !

I assume this is a really basic question but I'm a JQuery rookie :) so
please be indulgent :)

I would like to get an element by its id but just on a specific node.
I only see on the web things like that : $("#myId"). That is the
equivalent of window.document.getElementById("myId"). But for me that
should be something like myNode.getElementById("myId").

Is that clear?...

Thanks in advance