XUL and jquery

XUL and jquery


Hy!
I'm trying to do the followind into a firefox 3 extension:
alert($('<div id="content">abc</div>').html());
and it always alerts "null" instead of "abc".
I understand that jquery should work also on XUL, with few exceptions
at the startup, but this appears not to work.
What I want to achieve, is to parse an HTML that came from an ajax
call.
Is there a fix for this problem, or maybe someone has another solution
to this problem...?
Thank you in advance.