I need some basic help with coding main navigation menu for

I need some basic help with coding main navigation menu for a non-WP page.
I have provided the HTMl and CSS code via links (http://pastebin.com/0mCRr9Vg, http://pastebin.com/A80gXzAL) but need help with making the "Knowledge Center" menu item a drop down menu like it is on the site homepage:
http://portal.mindsharehr.com/

Can you suggest what code needs to be added to make the menu look like the homepage main menu?

Thanks
Shireen