function togglePreview(_pic) {
	var elem = Element.descendants('thumbs');
	for (i = 0; i < elem.length; i++) {
		elem[i].className = '';
	}
	var tmp = _pic.src.split('_thumb');
	_pic.className = 'selected';
	$('prevAnchor').href = tmp[0]+'_big.jpg';
	$('prevImage').src = tmp[0]+'_normal.jpg';
}