(function($) {
	$.fn.slideshow = function(options) {

		var settings = {
			// user editable settings
			autoRun: true,
			delay: 5000,
			dissolve: 70,
			showCaptions: false,
			centerImage: false
		};

		var sys = {
			// function parameters
			elem: null,
			slides: [],
			captions: [],
			current: 0,
			timer: null,
			pause: false
		};

		/* 
			sets a slides opacity
		***************************************/
		function setOpacity(o) {
			if (parseFloat(o.t) > 1) {
				o.t = 1.0;
				return;
			}
			$(o).css({
				"opacity": parseFloat(o.t),
				"MozOpacity": parseFloat(o.t),
				"filter": "alpha(opacity=" + (parseFloat(o.t) * 100) + ")"
			});
		}

		/* 
			sets the slide and handles dissolves
		***************************************/
		function setSlide() {
			var o = parseFloat(sys.slides[sys.current].t);
			var x = sys.slides[sys.current + 1] ? sys.current + 1 : 0;
			var no = parseFloat(sys.slides[x].t);
			o -= 0.05;
			no += 0.05;
			$(sys.slides[x]).css({
				"display": "block"
			});
			sys.slides[sys.current].t = parseFloat(o);
			sys.slides[x].t = parseFloat(no);
			setOpacity(sys.slides[sys.current]);
			setOpacity(sys.slides[x]);
			if (sys.captions[sys.current] && sys.captions[x]) {
				$(sys.captions[x]).css({
					"display": "block"
				});
				sys.captions[sys.current].t = parseFloat(o);
				sys.captions[x].t = parseFloat(no);
				setOpacity(sys.captions[sys.current]);
				setOpacity(sys.captions[x]);
			}
			if (o <= 0) {
				$(sys.slides[sys.current]).css({
					"display": "none"
				});
				if (sys.captions[x]) {
					$(sys.captions[x]).css({
						"display": "block"
					});
					$(sys.captions[sys.current]).css({
						"display": "none"
					});
				}
				sys.current = x;
				if (!sys.pause) {
					sys.timer = setTimeout(setSlide, settings.delay);
				}
			} else {
				if (!sys.pause) {
					sys.timer = setTimeout(setSlide, settings.dissolve);
				}
			}
		}

		/* 
			pauses the slideshow
		***************************************/
		function pause() {
			sys.pause = true;
			if (sys.timer) {
				clearTimeout(sys.timer);
				sys.timer = null;
			}
			$(sys.elem).find("div.ts_slideshow_pause_wrapper").fadeIn("fast");
		}

		/* 
			resumes the slideshow
		***************************************/
		function resume() {
			sys.pause = false;
			$(sys.elem).find("div.ts_slideshow_pause_wrapper").fadeOut("fast");
			sys.timer = setTimeout(setSlide, 0);
		}

		/* 
			initialize the slideshow & slides
		***************************************/
		function init() {

			// need to make sure the positioning is set for the main container.
			// it needs to be set to anything other than STATIC
			if ($(sys.elem).css("position") === "" || $(sys.elem).css("position") === "static") {
				$(sys.elem).css("position", "relative");
			}

			// create our main slideshow wrapper
			var i, wrapper = $("<div>").css({
				"display": "block",
				"width": "0px",
				"height": "0px",
				"position": "absolute",
				"overflow": "hidden",
				"cursor": "pointer"
			}).addClass("ts_slideshow_wrapper"),
			pauseBlock = $("<div>").css({
				"display": "none",
				"position": "absolute",
				"z-index": "10"
			}).html("Stop...").addClass("ts_slideshow_pause_wrapper");

			// loop through the images and initialize some settings
			$(sys.elem).find("img").each(function() {
				sys.slides.push($(this).get(0));
			}).css({
				"position": "absolute",
				"top": "0px",
				"left": "0px"
			}).wrapAll($(wrapper));
			$(sys.elem).find("div.ts_slideshow_wrapper").append(pauseBlock).bind("mouseenter", function() {
				pause();
			}).bind("mouseleave", function() {
				resume();
			});
			$(sys.elem).find("br").css({
				"display": "none"
			});

			$(sys.elem).css({
				"display": "block"
			});

			// center the image? we need the images to have the display set to none in order to start the transitions
			// but in order to get the width and height in Internet Explorer, they need to be visible... (or display=block)
			$(sys.elem).find("img").each(function() {
				var i = this;
				if (settings.centerImage) {
					$(i).css({
						"display": "none",
						"top": settings.centerImage ? parseInt(($(sys.elem).height() - $(i).attr("height")) / 2, 10) + "px": "0px",
						"left": settings.centerImage ? parseInt(($(sys.elem).width() - $(i).attr("width")) / 2, 10) + "px": "0px"
					});
				} else {
					$(i).css({
						"display": "none"
					});
				}
			});

			// captions?
			for (i = 0; i < sys.slides.length; i++) {
				sys.slides[i].t = 0.0;
				if (settings.showCaptions) {
					if ($(sys.slides[i]).attr("alt") !== "") {
						var cap = $("<span>").css({
							"position": "absolute",
							"display": "none",
							"width": "100%",
							"height": "auto"
						}).addClass("ts_slideshow_caption_wrapper").html($(sys.slides[i]).attr("alt"));
						$(sys.slides[i]).after(cap);
						sys.captions.push($(sys.slides[i]).next("span"));
						sys.captions[i].t = 0.0;
					} else {
						sys.captions.push(null);
						sys.captions[i].t = 0.0;
					}
				}
			}

			// make the first slide and/or caption visisable
			if (sys.slides.length > 0) {
				$(sys.slides[0]).css({
					"display": "block"
				});
				sys.slides[0].t = 1.0;
				if (sys.captions[0]) {
					$(sys.captions[0]).css({
						"display": "block"
					});
					sys.captions[0].t = 1.0;
				}
				// show our main elem, if it was hidden
				$(sys.elem).find(".ts_slideshow_wrapper").css({
					"width": $(sys.elem).width(),
					"height": $(sys.elem).height()
				});
			}

		}

		function start() {
			sys.timer = setTimeout(setSlide, settings.delay);
		}

		/* 
			set up any user passed variables
		***************************************/
		if (options) {
			$.extend(settings, options);
		}

		/* 
			begin
		***************************************/
		return this.each(function() {
			sys.elem = this;
			init();
			if (settings.autoRun) {
				start();
			}
		});

	};
})(jQuery);