function initLeftMenu() {
	var menuElement = document.getElementById('menu');
	var menuLis = menuElement.getElementsByTagName('LI');
	for (var i=0;i<menuLis.length;i++) {
		if (menuLis[i].lastChild.tagName=='UL') {
			// nastavime javascriptem css styly, abychom s nimi mohli pracovat
			if (menuLis[i].lastChild.className=='menu-active') {
				menuLis[i].lastChild.style.display='block';
				openedMenu.push(menuLis[i].lastChild);
			}
			else
				menuLis[i].lastChild.style.display='none';
			// propojime element A s elementem UL
			menuLis[i].firstChild.relatedElement=menuLis[i].lastChild;
			
			//kazdemu elementu A nastavime onclick event handler
			menuLis[i].firstChild.onclick=function () {
				//pokud je element UL viditelny, schovame jej
				if (this.relatedElement.style.display=='block') {
					this.relatedElement.style.display='none';
				}
				//pokud neni viditelny zjistime si ostatni otevrena menu, ktere schovame (pokud nejsou rodicem oteviraneho), a element UL zobrazime
				else {

                	var counter=openedMenu.length;
                	var nalezeno=false;
                	while(counter>0 && !nalezeno) {
						//pokud neni posledni level otevreneho menu...
                		if (
                			//...zaroven menu ktere se ma otevirat
                			openedMenu[counter-1]!==this.relatedElement &&
                			//...rodicovskym menu
                			openedMenu[counter-1]!==this.parentNode.parentNode
                		) {
                			var toHide=openedMenu.pop();
                			toHide.style.display="none";
	                		--counter;
                		}
                		else {
                			nalezeno=true;
                		}
                	}
					openedMenu.push(this.relatedElement);
					this.relatedElement.style.display='block';
				}
				return false;
			}
		}
	}
}

if (document.createElement && document.getElementsByTagName) {
	addEventSimple(window,'load',initLeftMenu);
	openedMenu=new Array();
}