Dynamically Adding Html To A Page

I have two problems that I suspect will be bread-and-butter problems for the
more experienced guys on here, but I'm not the greatest with js.

NB: Code snippets at the bottom

The first problem is that after a bit of fiddling I'm getting am 'Object
Expected' error when I click on the Depot dropdown which I can't seem to get
round. The code I had was working OK but then I cut it all out, tidied it
all up, and put it back in and now it doesnt work.

The second problem is a 'How do I...'. I'm using an XML data island to
retrieve some data without submitting the form. In the first example, when
the user selects a Customer, the Depot list is updated with all the depots
for that customer; This all works fine. What I want to do now is retrieve
some more data when the Depot is selected.

I have the XML bits working; the js code snippet correctly output a series
of msgboxes with the correct value in (or at least it did until I introduced
the Object Expect error!).

However, I'm unsure as to how to display this information on the page. The
XML contains a series of Part No's and Quantities, which I'd like to display
in a table towards the bottom of the screen. The problem is that I don't
know how to dynamically create and populate this table.

The only caveat is that I dont want to show the table if no values are
returned from the query....