function openSubMenu(subMenu,buttonId){
	if(subMenu){
		var sidebar = document.getElementById('sidebar');
		var subMenuAll = sidebar.getElementsByTagName("LI");
		var buttonAll = sidebar.getElementsByTagName("A");
		for(i=0; i < buttonAll.length; i++){
			if(buttonAll[i].id != ''){
				buttonAll[i].className = 'menu_li_a';
				}
			}
		// Gasim sve pod menije
		for(i=0; i < subMenuAll.length; i++){
			if(subMenuAll[i].className == 'subMenu'){
				subMenuAll[i].style.display = 'none';
				}
			}
		// Palim izabrani pod meni
		var button = document.getElementById(buttonId);
		button.className = 'menu_li_a_hover';
		var subMenu = document.getElementById(subMenu);
		subMenu.style.display = 'block';
		}
	}