var preLoadUrl = new Array(
	'../img/navi_home_on.gif',
	'../img/navi_manual_on.gif',
	'../img/navi_regist_on.gif',
	'../img/navi_login_on.gif',
	'../img/navi_inquiry_on.gif'
);
var preLoad = new Array(preLoadUrl.length);
for(i = 0; i < preLoad; i++){
    preLoad[i] = new Image();
    preLoad[i].src = preLoadUrl[i];
}


function smartRollover() {
	if(document.getElementsByTagName) {
		var images = document.getElementsByTagName("img");
		for(var i=0; i < images.length; i++) {
			if(images[i].getAttribute("src").match("_off."))
			{
				images[i].onmouseover = function() {
					this.setAttribute("src", this.getAttribute("src").replace("_off.", "_on."));
				}
				images[i].onmouseout = function() {
					this.setAttribute("src", this.getAttribute("src").replace("_on.", "_off."));
				}
			}
		}
	}
}
if(window.addEventListener) {
	window.addEventListener("load", smartRollover, false);
}
else if(window.attachEvent) {
	window.attachEvent("onload", smartRollover);
}