sub menu access on mobile

I need a bit of help figuring out how to make the sub menus under /gallery available on a mobile devise.

http://www.countrysidecabinetshop.net/gallery.html

After clicking on it I need it to stay open until a selection is made or clicked on the main page to close the menu.

Thanks,

 

Here´s a tutorial I found on the web. Didn´t test it

http://osvaldas.info/drop-down-navigation-responsive-and-touch-friendly

 

Was hoping I could do it with css code. Don't really know jquery or javascript