if (document.images) {
		var img1on = new Image();
		img1on.src = "../images/top_click.gif"; 
		var img1off = new Image();
		img1off.src = "../images/top.gif";

		var img2on = new Image();
		img2on.src = "../images/taberu_click.gif"; 
		var img2off = new Image();
		img2off.src = "../images/taberu.gif";

		var img3on = new Image();
		img3on.src = "../images/tomaru_click.gif"; 
		var img3off = new Image();
		img3off.src = "../images/tomaru.gif";

		var img4on = new Image();
		img4on.src = "../images/kau_click.gif"; 
		var img4off = new Image();
		img4off.src = "../images/kau.gif";

		var img5on = new Image();
		img5on.src = "../images/tanosimu_click.gif"; 
		var img5off = new Image();
		img5off.src = "../images/tanosimu.gif";

	}

	function On(name) {
		if (document.images) {
			document.images[name].src = eval(name + 'on.src');
		}
	}

	function Off(name) {
		if (document.images) {
			document.images[name].src = eval(name + 'off.src');
		}
	}