var imageIdx = 0;

function switchImage(back) {
	
	if (!back && ++imageIdx > imageCount - 1) {
		 imageIdx = 0;
	} else if (back && --imageIdx < 0) {
		imageIdx = imageCount - 1;
	}
		
	var id = imageIds[imageIdx];
	
	console.log('id: '+ id +', imageIdx: '+ imageIdx);
	
	if ($("product-main-image").href && productImages[id].huge.length > 0) {
		$("product-main-image").href = productImages.baseUrl + "/" + productImages[id].huge;
		$("product-main-image").setStyle({
			backgroundImage: "url("+ productImages.baseUrl + "/" + productImages[id].large +")"
		 });
	}
	
	$('imageno').innerHTML = imageIdx + 1;
}