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."));
				}
			}
		}
	}
}

function navi_btn() {
	var url = location.href;
	var src_id = "";
	var class_id = "";
	if(url.match("/study/")){
		class_id = document.getElementById('study_navi');
		if(class_id){
			class_id.className = "dis_open";
			src_id = document.getElementById('study_btn');
			src_id.src = src_id.src.replace( "_cl.","_op.");
		}
	}
	else if(url.match("/enjoy/")){
		class_id = document.getElementById('enjoy_navi');
		if(class_id){
			class_id.className = "dis_open";
			src_id = document.getElementById('enjoy_btn');
			src_id.src = src_id.src.replace("_cl.", "_op.");
		}
	}
	else if(url.match("/profit/")){
		class_id = document.getElementById('profit_navi');
		if(class_id){
			class_id.className = "dis_open";
			src_id = document.getElementById('profit_btn');
			src_id.src = src_id.src.replace("_cl.", "_op.");
		}
	}
}

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