function update_gallery_show(pImage){
	pImage = new Number(pImage);
	if(!isNaN(pImage) && pImage >= 0){
		$('show_image').style.backgroundImage = 'url(creations/' + creations[pImage].photo + '_photo.jpg)' ;
		$('btn_main').href = creations[pImage].link ;
		idRef = pImage ;
		return false;
	}
}

function update_next_show(){
	var next = idRef + 1 ;
	if(!creations[next]) next = 0 ;
	update_gallery_show(next);
}

function update_previous_show(){
	var prev = idRef - 1 ;
	if(!creations[prev]) prev = new Number(creations.length - 1) ;
	update_gallery_show(prev);
}