Dropdown menu(i.e SubMenu) not wporking properly in Firefox

Question

Hello

I have a Drop down Menu written with CSS and javascript that is actually working fine in IE and Google Crome but isn't working properly in Firefox.

Here is my website : http://www.competentsystems.com/CSystems/  (In this website in Menubar  Solutions,Services and Industries.. have Submenus(Hover Vertical sub menus) those are not working properly.

Thanks