Yes, the menu can be made to display horizontally, with a little bit of work. You didn't provide a URL that shows the menu you are using, so I will use a dummy menu that I created.
Here is a link to DHTML Drop Down Menu - Vertical. This shows a simple dropdown menu as it is generated from Bravenet's DHTML Menu Generator. It only contains three main categories with three or for dropdowns in each category.
This next link, DHTML Drop Down Menu - Horizontal, is the exact same menu, modified to display horizontally. Only the main categories display horizontally. The dropdown items are still vertical. I think that's what your aiming at anyway.
Bravenet's DHTML Menu Generator uses
structures to create the menu. But
structures are block structures which, by default, generate new lines. It's possible to declare them to be "inline" structures, but that causes some issues with the menu shifting around.
The simplest way to make it display horizontally is to create a table and confine each main catagory, and it's submenu, to a table cell. The second example is simply a table with one vertical column and three horizontal cells. You can use your right mouse button to see the changes that I made. Note that I added one style to manage the width and positioning in the cells.
