// rollover
if (document.images) {
	myb1on = new Image();
	myb1on.src = "/images/btn_profile_on.gif";
	myb1off = new Image();
	myb1off.src = "/images/btn_profile.gif";
	myb2on = new Image();
	myb2on.src = "/images/btn_blog_on.gif";
	myb2off = new Image();
	myb2off.src = "/images/btn_blog.gif";
	myb3on = new Image();
	myb3on.src = "/images/btn_exhibition_on.gif";
	myb3off = new Image();
	myb3off.src = "/images/btn_exhibition.gif";
	myb4on = new Image();
	myb4on.src = "/images/btn_book_on.gif";
	myb4off = new Image();
	myb4off.src = "/images/btn_book.gif";
	myb5on = new Image();
	myb5on.src = "/images/btn_shop_on.gif";
	myb5off = new Image();
	myb5off.src = "/images/btn_shop.gif";
}
function imgOn(imgName) {
	if (document.images) {
		document[imgName].src=eval(imgName+"on.src");
	}
}
function imgOff(imgName) {
	if (document.images) {
		document[imgName].src=eval(imgName+"off.src");
	}
}