var imgs = new Array();
window.onload = preload;
function preload(){
		addParameters();
}


function addParameters(){
		var ele = document.getElementById('header').getElementsByTagName('ul')[0].getElementsByTagName('li');
		var eleLen = ele.length;
		var img, str, on, off
		for(var i=0;i<eleLen;i++){
				img = ele[i].childNodes[0].childNodes[0];
				str = String(img.id);
				on = 'imageSwapOn(\'' + img.id + '\');';
				off = 'imageSwapOff(\'' + img.id + '\');';
				imgs[str] = new Array();
				imgs[str][0] = new Image();
				imgs[str][1] = new Image();
				imgs[str][0].src = '/images/menu/' + img.id + '.gif';
				imgs[str][1].src = '/images/menu/' + img.id + '2.gif';
				if (document.all){
						img.setAttribute('onmouseover', new Function(on));
						img.setAttribute('onmouseout', new Function(off));
				} else {
						img.setAttribute('onmouseover', on);
						img.setAttribute('onmouseout', off);
				}
		}
}

function imageSwapOn(id){
		var ele = document.getElementById(id);
		ele.src = imgs[id][1].src;
}

function imageSwapOff(id){
		var ele = document.getElementById(id);
		ele.src = imgs[id][0].src;
}