// first thumbnail is always the current image, so it
	// should start out being selected
	$('#photo_gallery ul li:first-child img').addClass('selected');

	// set the last thumbnail's margin to 0
	$('#photo_gallery ul li:last-child').addClass('last');
	
	// all thumbnails should begin with lower opacity
	$('#photo_gallery ul img').animate({ opacity: 0.75 }).hover(
		
		// on mouseover:
		function(e) {
			var thumbnail = $(e.target);
			
			// selected status should be removed from all thumbnails
			thumbnail.parent().siblings().children().removeClass('selected');
			
			// thumbnail opacity should go back up to 100%
			thumbnail.stop().animate({ opacity: 1 }, "fast");
			
			// thumbnail should become selected
			thumbnail.addClass('selected');
			
			// main image should be updated with thumbnail image
			var new_photo = thumbnail.attr('src').replace('_thumbnail','');
			$('#photo_gallery img#main').attr('src', new_photo);
		},
		
		// on mouseout:
		function(e) {
			
			// opacity should drop back down
			$(this).stop().animate({ opacity: 0.75 });
		}
	);