if (document.images) {
	var img1on = new Image();
	img1on.src = "img/top_b.png"; 
	var img1off = new Image();
	img1off.src = "img/top_a.png"; 

	var img2on = new Image();
	img2on.src = "img/con_b.png";
	var img2off = new Image();
	img2off.src = "img/con_a.png";

	var img3on = new Image();
	img3on.src = "img/cs_b.png";
	var img3off = new Image();
	img3off.src = "img/cs_a.png";

	var img4on = new Image();
	img4on.src = "img/str_b.png";
	var img4off = new Image();
	img4off.src = "img/str_a.png";

	var img5on = new Image();
	img5on.src = "img/ch_b.png";
	var img5off = new Image();
	img5off.src = "img/ch_a.png";

	var img6on = new Image();
	img6on.src = "img/st_b.png";
	var img6off = new Image();
	img6off.src = "img/st_a.png";

	var img7on = new Image();
	img7on.src = "img/do_b.png";
	var img7off = new Image();
	img7off.src = "img/do_a.png";
}


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');
	}
}