$(document).ready(function(){

	var scroll_amount        = 20;
	var nav_animation_time   = 10;
	var max_pos              = -$('#gallery_scroll .thumbscroll').width()+$('#gallery_scroll .thumbs').width();
	var thumb_animation_time = 300;
	var left_interval;
	var right_interval;


	// left navigation
	LeftNav = function(){
		var curr_pos = parseInt($('#gallery_scroll .thumbscroll').css('marginLeft'));

		if(curr_pos <= -scroll_amount) $('#gallery_scroll .thumbscroll').animate({marginLeft: parseInt($('#gallery_scroll .thumbscroll').css('marginLeft'))+scroll_amount}, nav_animation_time);
		else $('#gallery_scroll .thumbscroll').animate({marginLeft: 0}, nav_animation_time);
	};

	$('#gallery_scroll .left').mousedown(function(){left_interval = setInterval(LeftNav, 40)});
	$('#gallery_scroll .left').mouseup(function(){clearInterval(left_interval)});
	$('#gallery_scroll .left').mouseout(function(){clearInterval(left_interval)});

	// right navigation
	RightNav = function(){
		var curr_pos = parseInt($('#gallery_scroll .thumbscroll').css('marginLeft'));

		if(curr_pos >= max_pos+scroll_amount) $('#gallery_scroll .thumbscroll').animate({marginLeft: parseInt($('#gallery_scroll .thumbscroll').css('marginLeft'))-scroll_amount}, nav_animation_time);
		else $('#gallery_scroll .thumbscroll').animate({marginLeft: max_pos}, nav_animation_time);
	};

	$('#gallery_scroll .right').mousedown(function(){right_interval = setInterval(RightNav, 40)});
	$('#gallery_scroll .right').mouseup(function(){clearInterval(right_interval)});
	$('#gallery_scroll .right').mouseout(function(){clearInterval(right_interval)});

	// thumb hover
	$('#gallery_scroll .thumb').hover(function(){$(this).addClass('thumbhover');},
									  function(){$(this).removeClass('thumbhover');});

	// thumb click
	$('#gallery_scroll .thumb').click(function(){
		var thumbthis = $(this);
		$('#gallery_scroll .imagecontent').stop();
		$('#gallery_scroll .imagecontent').animate({opacity: 0.0}, thumb_animation_time, function(){
							$('#gallery_scroll .imagecontent').css('display', 'none');
							$('#gallery_scroll #image'+thumbthis.attr('id')).css('display', 'block');
							$('#gallery_scroll #image'+thumbthis.attr('id')).css('opacity', '0.0');
							$('#gallery_scroll #image'+thumbthis.attr('id')).stop();
							$('#gallery_scroll #image'+thumbthis.attr('id')).animate({opacity: '1.0'}, thumb_animation_time);
		});
	});


});