var lis = document.getElementsByTagName("li");
for(var i = 0; i<lis.length; i++){
	if(lis[i].className.match(/submenu/gi)){
		lis[i].onmouseover = function(){
			this.lastClass = this.className;
			this.className = this.className + " hover";
		};
		lis[i].onmouseout = function(){
			this.className = this.lastClass;
		};
	}
}