The web site I have created utilities a horizntal navigation bar of parent pages and drop down menus for the child pages. The web site and drop down menus works fine on PC internet explorer versions 8 and 9, Google Chrome, and Safari for the PC. However, when I view the web site on an iphone or android phone, the drop down menus on the navigation bar do not work. Nothing drops down. Everything else on the web site works great on the phones (including news ticker, movie, text, links, and pics). Is there a some setting or HMTL code that is required for the navigation bar for the drop down menus to work properly on mobile devices?

Thanks.