listmenu = function(id) {
	document.getElementById(id).className = "listmenu";
	var submenus = document.getElementById(id).getElementsByTagName("ul");
	for(i=0;i<submenus.length;i++) {
		submenus[i].className = "listmenu";
	}
	knoppen = document.getElementById(id).getElementsByTagName("li");
	for(i=0;i<knoppen.length;i++) {
		var knop = knoppen[i];
		knop.style.position = "relative";
		if(knop.getElementsByTagName("ul").length) {
			var submenu = knop.getElementsByTagName("ul")[0];
			submenu.style.visibility = 'hidden';
			submenu.style.display = 'block';
			submenu.style.position = 'absolute';
			var vanlinks = knop.offsetWidth - 4;
			submenu.style.left = vanlinks + 'px';
			submenu.style.top = '-1px';

			var sp1 = document.createElement("img");
			sp1.setAttribute("src", "/systeem/listmenu/submenu.gif");
			sp1.className = "sub";
			sp1.style.position = 'absolute';
			sp1.style.left = (vanlinks - 6) + 'px';
			sp1.style.top = '8px';
			knop.insertBefore(sp1, submenu);

			knop.onmouseover = function() {
				this.className = "over";
				this.getElementsByTagName("ul")[0].style.visibility = 'visible';
			}
			knop.onmouseout = function() {
				this.className = "";
				this.getElementsByTagName("ul")[0].style.visibility = 'hidden';
			}
		} else {
			knop.onmouseover = function() {
				this.className = "over";
			}
			knop.onmouseout = function() {
				this.className = "";
			}
		}
		knop.onclick = function(ev) {
			var tg = navigator.userAgent.indexOf("MSIE") != -1 ? window.event.srcElement : ev.target;
			if(this == tg) {
				var a = this.getElementsByTagName("a")[0];
				if(a && a.parentNode == this && a.hasAttribute("href")) {
					location.href = a.getAttribute("href");
				} else {
					alert('auw!');
				}
	    }

		}
	}

}