Hover element problem

ok so i have a menu,which is simply a html list. i apply a li:hover to change the background color of any <li> element when i move the mouse over them. but when i’m in a certain section of the site, its corresponding button is “selected” and i don’t want its background to change when i move my mouse over it. is there a way to avoid the hover over one element? or should i mess up with javascript? is there a pure CSS solution for this?