function image_on (img_num,image_name) {
	document.images[img_num].src = 'images/'+image_name;
}

function image_off (img_num,image_name) {
	document.images[img_num].src = 'images/'+image_name;
}

function rotate_image (img_num, image_name) {
	document.images[img_num].src = 'images/'+image_name;
}