//ロールオーバーファンクション
function initRO(){
	var btns_obj = document.getElementsByName("ro_btn");
	var btns_r_src = new Array();
	
	for (var i=0; i < btns_obj.length; i++){
		
		var img_src = btns_obj[i].getAttribute("src");
		var split_src = img_src.split("_d.");
		var img_r_src = split_src[0] + "_r." + split_src[1];
		
		var img_r = new Image();
		img_r.src = img_r_src;
		
		btns_obj[i].onmouseover = function(){
			var img_src = this.getAttribute("src");
			var split_src = img_src.split("_d.");
			if (1 < split_src.length){
				var img_r_src = split_src[0] + "_r." + split_src[1];
				this.setAttribute("src",img_r_src);
			}
		};
		btns_obj[i].onmouseout = function(){
			var img_r_src = this.getAttribute("src");
			var split_src = img_r_src.split("_r.");
			if (1 < split_src.length){
				var img_src = split_src[0] + "_d." + split_src[1];
				this.setAttribute("src",img_src);
			}
		};
	}
}