function switchMenu(id1,id2,w)
{
	document.getElementById(w+id1).style.display = '';
	document.getElementById(w+'menu'+id1).className = 'tab_b';
	document.getElementById(w+id2).style.display = 'none';
	document.getElementById(w+'menu'+id2).className = 'tab_a';
}

var cacheImgArr=[
	'images/nav_1_bg.gif',
	'images/nav_1_bg.jpg',
	'images/nav_2_bg.gif',
	'images/nav_2_bg.jpg',
	'images/nav_3_bg.gif',
	'images/nav_3_bg.jpg',
	'images/nav_4_bg.gif',
	'images/nav_4_bg.jpg',
	'images/nav_5_bg.gif',
	'images/nav_5_bg.jpg'
	];
	
	function imgCache(){
		for(i=0;i<cacheImgArr.length;i++)
			hkuc_cache_img(cacheImgArr[i]);
	}
	
	addLoadEvent(imgCache);
	
(function (bool){
	if (bool){
		window.__defineGetter__("event", function (){
			var o=arguments.callee;
			do{
				if (o.arguments[0] instanceof Event)return o.arguments[0];
			}while (o=o.caller);
			return null;
		});
        HTMLElement.prototype.contains = function(o){return false;
		  return !!(this.compareDocumentPosition(o) & 16);
		}
	}
})(/Firefox/.test(window.navigator.userAgent));

	function display_menu(o,d){
		divObj=document.getElementById(o.id+("_div"));
		if(!divObj)return;
		if(d){
			divObj.style.display="block";
			o.getElementsByTagName('a')[0].className='on';
		}
		else{			
			e = window.event;
			if(!o.contains(e.toElement) && !divObj.contains(e.toElement)){
				divObj.style.display="none";
				o.getElementsByTagName('a')[0].className='';
			}
		}
	}
	function keep_menu(o,d){
		orgObj=document.getElementById(o.id.replace(/\_div$/,""));
		if(!orgObj)return;
		if(d){
			o.style.display="block";
			orgObj.getElementsByTagName('a')[0].className='on';
		}
		else{
			e = window.event;
			if(!orgObj.contains(e.toElement) && !o.contains(e.toElement)){
				o.style.display="none";
				orgObj.getElementsByTagName('a')[0].className='';
			}
		}
	}