function changePage(year, newPage) {
	if ( ( newPage >= minPage ) && ( newPage <= maxPage ) ) {
		if ( newPage == minPage ) {
			$('prev').style.visibility = 'hidden';
		} else {
			$('prev').style.visibility = 'visible';
		}

		if ( newPage == maxPage ) {
			$('next').style.visibility = 'hidden';
		} else {
			$('next').style.visibility = 'visible';
		}

		page = newPage;
		$('pageNumber').innerHTML = page;
		new Ajax.Updater('thumbnails', 'pictures.php', 
		{
			method: 'post',
			parameters: 'page='+ newPage +'&year='+ year
		});
	}
}