// JavaScript Document

function swapImage(tagName,className){
	var reg = (className instanceof Array)?className.join("|"):className;
	var s = '^(.+\s)?('+reg+')(\s.+)?$';
	var swapClass = new RegExp(s);
	
	var chk = document.getElementsByTagName(tagName);
	if(tagName != "img"){
		for(var i = 0;i < chk.length;i++){
			if(chk[i].className.match(swapClass)){
				var obj = chk[i].firstChild;
				var ext = obj.src.slice(-3);
				if(obj.src.slice(-6) != "_o." + ext){
					chk[i].onmouseover = function(){
						var img = this.firstChild.src.substring(0,this.firstChild.src.length - 4);
						this.firstChild.src = img + "_o." + ext;
					}
					chk[i].onmouseout = function(){
						var img = this.firstChild.src.substring(0,this.firstChild.src.length - 6);
						this.firstChild.src = img + "." + ext;
					}
				}
			}
		}
	}
	else{
		for(var i = 0;i < chk.length;i++){
			if(chk[i].className.match(swapClass)){
				var obj = chk[i];
				var ext = obj.src.slice(-3);
				if(obj.src.slice(-6) != "_o." + ext){
					chk[i].onmouseover = function(){
						var img = this.src.substring(0,this.src.length - 4);
						this.src = img + "_o." + ext;
					}
					chk[i].onmouseout = function(){
						var img = this.src.substring(0,this.src.length - 6);
						this.src = img + "." + ext;
					}
				}
			}
		}
	}
}

window.onload = function(){
	swapImage("a","menu-item");
	swapImage("a","navi");
}