function operateMenu() {
				var menu=document.getElementById('subitem-menu');
				var Lists=menu.getElementsByTagName('LI');
				for(var i=0; i<Lists.length; i++) {
					Lists[i].onmouseover=function() {
						this.className=(this.className=='drop')?'':'drop';
					}
					Lists[i].onmouseout=function() {
						this.className=(this.className=='drop')?'':'drop';
					}
				}
			}

			function operateTreeMenu() {
				var menu=document.getElementById('menu');
				var Links=menu.getElementsByTagName('A');

				for(var i=0; i<Links.length; i++) {
					Links[i].onclick=function() {
						var Lists=this.parentNode.parentNode.getElementsByTagName('UL');

						for(var j=0; j<Lists.length; j++)
							Lists[j].style.display='none';

						if(
							this.nextSibling && this.nextSibling.nextSibling &&
							this.nextSibling.nextSibling.tagName=='UL'
						)
							this.nextSibling.nextSibling.style.display='block';
					}
				}
			}