The Horizontal Menu has already been created for you. Generally UAB templates are designed for you to create individual left sidebars for each area of your site. The horizontal navigation menu is used to point to the left sidebar menus using an alias link.

horizontalmenu

To access the menu select Menus > Horizontal Navigation-DO NOT DELETE from the Menu dropdown at the top of the page.

Locate the Horizontal Nav menu

TIP: Make sure your sidebar menu have been created before you begin.

Click on New to add a new menu item to the Horizontal Menu.  Enter a Title (the Title will appear on the Horizontal Nav menu). Click on the Select icon beside the Menu Item Type.  We want to add a menu item called an "Alias," which is simply a menu item that points to another menu.
Locate the Select Menu Item icon
Under System Links, choose "Menu Item Alias."
Locate the menu item alias

Next, we want to point our alias to the correct sidebar menu. Under Menu Item, select the menu that should be linked to the horizontal menu item (SUGGESTION:  Pick Area 5 Sidebar)
aliasitem
TIP: The Alias field is used to create a "friendly" address.  In the example below, a user could type in http://www.uab.edu/whateverdomain/area5 to reach the area 5 landing page.You may change the alias to create friendly addresses or an alias will be automatically assigned upon saving.
Creat ealias friendly


That's it!  Just click "Save & Close" and you can preview your new menu. 
Preview of new menu item

TIP:  To create a drop down menu, complete the steps above and select a Parent Item from the drop down menu.