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.", "_over."));
			  }
			  images[i].onmouseout = function() {
				this.setAttribute("src", this.getAttribute("src").replace("_over.", "_off."));
			  }
			}
		}
	}
}

if(window.addEventListener) {
	window.addEventListener("load", smartRollover, false);
}
else if(window.attachEvent) {
	window.attachEvent("onload", smartRollover);
}else{
window.onload = smartOver;
}

//preload
Images = new Array();

Images[0]= "common/img/navi_01_on.gif";
Images[1]= "common/img/navi_02_on.gif";
Images[2]= "common/img/navi_03_on.gif";
Images[3]= "common/img/navi_04_on.gif";
Images[4]= "common/img/navi_05_on.gif";
Images[5]= "common/img/navi_06_on.gif";

function PreloadImg(){
	for(i=0; i<Images.length; i++){
		ImageName = "Image"+ i;
		var ImageName = new Image();
		ImageName.src = Images[i];
	}
}