FF-1.5 keyboard shortcut to Search field ...

Hi, thanks for reading this.

I'm using Firefox-1.5 and Windows XP x64.  No problems at all!
But I'm looking for help using keyboard shortcuts.

I'm aware that CTRL-k will jump the cursor to the search field
(is that called the Search Bar?) and highlight all the text.
Fantastic.

Now how do I pull down and choose a different search engine
without using the mouse?

When I use the down arrow, it goes through my search history
rather than my search engine list.

Ok, thanks.
Matthew