// preload images
function preload(imgObj,imgSrc) {
	if (document.images) {
		eval(imgObj+' = new Image()')
		eval(imgObj+'.src = "'+imgSrc+'"')
	}
}

// image flipper
function changeImage(layer,imgName,imgObj) {
	if (document.images) {
		if (document.layers && layer!=null) eval('document.'+layer+'.document.images["'+imgName+'"].src = '+imgObj+'.src')
		else document.images[imgName].src = eval(imgObj+".src")
	}
}

<!--
preload('designscreen','images/designscreen.jpg');

preload('bookoff','images/book.gif');
preload('posteroff','images/poster.gif');
preload('illustrationoff','images/illustration.gif');
preload('vioff','images/vi.gif');
preload('weboff','images/web.gif');
preload('cgoff','images/cg.gif');

preload('designbg','images/designbg.jpg');

preload('bookon','images/bookon.gif');
preload('posteron','images/posteron.gif');
preload('illustrationon','images/illustrationon.gif');
preload('vion','images/vion.gif');
preload('webon','images/webon.gif');
preload('cgon','images/cgon.gif');

preload('designscreenoff','images/designscreen.jpg');

preload('bookscreen','images/bookscreen.jpg');
preload('posterscreen','images/posterscreen.jpg');
preload('illustrationscreen','images/illustrationscreen.jpg');
preload('viscreen','images/viscreen.jpg');
preload('webscreen','images/webscreen.jpg');
preload('cgscreen','images/cgscreen.jpg');