// slide object
//==================================================
function slide(src,link,text,target,attr) {
	// This is the constructor function for the slide object.
	// It is called automatically when you create a new slide object.
	// For example: s = new slide();

	// Image URL,  Link URL, Text to display, Name of the target window ("_blank")
	this.src = src;
	this.link = link;
	this.text = text;
	this.target = target;

	// Custom duration for the slide, in milliseconds. ##############################
	// This is an optional parameter.
	// this.timeout = 3000

	// Attributes for the target window: width=n,height=n,resizable=yes or no,scrollbars=yes or no, toolbar=yes or no,location=yes or no,
	//    directories=yes or no, status=yes or no,menubar=yes or no,copyhistory=yes or no
	// Example: "width=200,height=300"
	this.attr = attr;

	// Create an image object for the slide
	if (document.images) {this.image = new Image(); }

	// Flag to tell when load() has already been called
	this.loaded = false;

	//--------------------------------------------------
	this.load = function() {
		// This method loads the image for the slide

		if (!document.images) { return; }
		if (!this.loaded) {
			this.image.src = this.src;
			this.loaded = true;
		}
	}

	//--------------------------------------------------
	this.hotlink = function() {
		// This method jumps to the slide's link.
		// If a window was specified for the slide, then it opens a new window.

		var mywindow;
		if (!this.link) return;
		if (this.target) {

			// Open new window - If window attributes are specified,
			// use them to open the new window otherwise copy attributes for originating window
			if (this.attr) {
				mywindow = window.open(this.link, this.target, this.attr);
			 } else {
				mywindow = window.open(this.link, this.target);
			}

			// Pop the window to the front
			if (mywindow && mywindow.focus) mywindow.focus();

		} else {
			// Open the link in the current window
			location.href = this.link;
		}
	}
}

//==================================================
// slideshow object
//==================================================
function slideshow( slideshowname ) {
	// This is the constructor function for the slideshow object.
	// It is called automatically when you create a new object.
	// For example: ss = new slideshow("ss");

	// Name of this object, repeat option, 
	this.name = slideshowname;
	this.repeat = true;

	// pre-fetch:  -1 = all; 0 = as used; n = n images ahead

	this.prefetch = -1;

	// IMAGE element on your HTML page.
	// For example, document.images.SLIDES1IMG
	this.image;

	// ID of a DIV element on your HTML page that will contain the text.
	// For example, "slides2text"
	// Note: after you set this variable,call update() method to update the display.
	this.textid;
	
	// Milliseconds to pause between slides.
	// Individual slides can override this.
	this.timeout = 6000;

	// Hook functions to be called before and after updating the slide
	// this.pre_update_hook = function() { }
	// this.post_update_hook = function() { }

	// These are private variables
	this.slides = new Array();
	this.current = 0;
	this.timeoutid = 0;

	//--------------------------------------------------
	// Public methods
	//--------------------------------------------------
	this.add_slide = function(slide) {
		// Add a slide. Example: SLIDES1.add_slide(new slide("s1.jpg", "link.html"))
	
		var i = this.slides.length;
		
		// Prefetch the slide image if necessary
		if (this.prefetch == -1) {
			slide.load();
		}
		this.slides[i] = slide;
	}

	//--------------------------------------------------
	this.play = function(timeout) {
		var timetmp;
		// This method implements the automatically running slideshow.
		// If you specify the "timeout" argument, then a new default
		// After the timeout, call this.loop()	
		
		// Make sure we're not already playing
		this.pause();
	
		// If the timeout argument was specified make it the new default
		if (timeout) {this.timeout = timeout;}
	
		// If the current slide has a custom timeout, use it;
		// otherwise use the default timeout
		if (typeof this.slides[ this.current ].timeout != 'undefined') {
			timetmp = this.slides[ this.current ].timeout;
		} else {
			timetmp = this.timeout;
		}
		this.timeoutid = setTimeout( this.name + ".loop()", timetmp);
	 
	}

	//--------------------------------------------------
	this.pause = function() {
		// This method stops the slideshow if it is automatically running.
		if (this.timeoutid != 0) {
			clearTimeout(this.timeoutid);
			this.timeoutid = 0;
		}
	}

	//--------------------------------------------------
	this.update = function() {
		// This method updates the slideshow image on the page

		// Make sure the slideshow has been initialized correctly
		if (! this.valid_image()) { return; }
	
		// Call the pre-update hook function if one was specified
		if (typeof this.pre_update_hook == 'function') {
			this.pre_update_hook();
		}

		// Convenience variable for the current slide
		var slide = this.slides[ this.current ];

		// Determine if the browser supports filters
		var dofilter = false;
		if (this.image && typeof this.image.filters != 'undefined' && typeof this.image.filters[0] != 'undefined') {
			dofilter = true;
		}

		// Load the slide image if necessary
		slide.load();
	
		// Apply the filters for the image transition
		if (dofilter) {

			// If the user has specified a custom filter for this slide,
			// then set it now
			if (slide.filter && this.image.style && this.image.style.filter) {
				this.image.style.filter = slide.filter;
			}
			this.image.filters[0].Apply();
		}

		// Update the image; play transition filters; update text
		this.image.src = slide.image.src;
		if (dofilter) {this.image.filters[0].Play();}
		this.display_text();

		// Call the post-update hook function if one was specified
		if (typeof this.post_update_hook == 'function') {
			this.post_update_hook();
		}

		// Do we need to pre-fetch images?
		if (this.prefetch > 0) {
		
			// Pre-fetch the next slide image(s)
			var next = this.current;
			var prev = this.current;
			var count = 0;
			do {

				// Get the next and previous slide number
				// Loop past the ends of the slideshow if necessary
				if (++next >= this.slides.length) next = 0;
				if (--prev < 0) prev = this.slides.length - 1;

				// Preload the slide image
				this.slides[next].load();
				this.slides[prev].load();

				// Keep going until we have fetched designated number of slides

			} while (++count < this.prefetch);
		}
	}

	//--------------------------------------------------
	this.goto_slide = function(n) {
		// This method jumpts to the slide number you specify. (-1=last)
		// If you use slide number -1, then it jumps to the last slide.
		
		if (n == -1) {n = this.slides.length - 1;}
		if (n < this.slides.length && n >= 0) {this.current = n;}
		this.update();
	}


	//--------------------------------------------------
	this.goto_random_slide = function() {
		// Picks a random slide (other than the current slide) and displays it.
		// See also: shuffle()

		var i;

		// Make sure there is more than one slide
		if (this.slides.length > 1) {

			// Generate a random slide number,
			// but make sure it is not the current slide
			do {
				i = Math.floor(Math.random()*this.slides.length);
			} while (i == this.current);
 
			// Display the slide
			this.goto_slide(i);
		}
	}


	//--------------------------------------------------
	this.next = function() {
		// This method advances to the next slide.
		if (this.current < this.slides.length - 1) {
			this.current++;
		} else if (this.repeat) {
			this.current = 0;
		}
		this.update();
	}


	//--------------------------------------------------
	this.previous = function() {
		// This method goes to the previous slide.
		if (this.current > 0) {
			this.current--;
		} else if (this.repeat) {
			this.current = this.slides.length - 1;
		}
		this.update();
	}


	//--------------------------------------------------
	this.shuffle = function() {
		// This method randomly shuffles the order of the slides.

		var i, i2, slides_copy, slides_randomized;

		// Create a copy of the array containing the slides in sequential order
		slides_copy = new Array();
		for (i = 0; i < this.slides.length; i++) {slides_copy[i] = this.slides[i];}

		// Create a new array to contain the slides in random order
		slides_randomized = new Array();

		// To populate the new array of slides in random order, loop through the existing slides, picking a random
		// slide, removing it from the ordered list and adding it to the random list.

		do {

			// Pick a random slide from those that remain
			i = Math.floor(Math.random()*slides_copy.length);

			// Add the slide to the end of the randomized array
			slides_randomized[ slides_randomized.length ] =
				slides_copy[i];

			// Remove the slide from the sequential array,
			// so it cannot be chosen again
			for (i2 = i + 1; i2 < slides_copy.length; i2++) {
				slides_copy[i2 - 1] = slides_copy[i2];
			}
			slides_copy.length--;

			// Keep going until we have removed all the slides

		} while (slides_copy.length);

		// Now set the slides to the randomized array
		this.slides = slides_randomized;
	}


	//--------------------------------------------------
	this.get_text = function() {
		// This method returns the text of the current slide
	
		return(this.slides[ this.current ].text);
	}


	//--------------------------------------------------
	this.get_all_text = function(before_slide, after_slide) {
		// Return the text for all of the slides.
		// For the text of each slide, add "before_slide" in front of the
		// text, and "after_slide" after the text. For example:
		// document.write("<ul>");document.write(s.get_all_text("<li>","\n"));document.write("<\/ul>");
	
		all_text = "";
	
		// Loop through all the slides in the slideshow
		for (i=0; i < this.slides.length; i++) {
			slide = this.slides[i];
			if (slide.text) {
				all_text += before_slide + slide.text + after_slide;
			}
		}
		return(all_text);
	}


	//--------------------------------------------------
	this.display_text = function(text) {
		// Display the text for the current slide
	
		// If the "text" arg was not supplied (usually it isn't),
		// get the text from the slideshow
		if (!text) {text = this.slides[ this.current ].text;}
		
		// Change the contents of the HTML element
		if (this.textid) {
			r = this.getElementById(this.textid);
			if (!r) { return false; }
			if (typeof r.innerHTML == 'undefined') { return false; }

			// Update the text
			r.innerHTML = text;
		}
	}


	//--------------------------------------------------
	this.hotlink = function() {
		// This method calls the hotlink() method for the current slide.
	
		this.slides[ this.current ].hotlink();
	}


	//--------------------------------------------------
	this.save_position = function(cookiename) {
		// Saves the position of the slideshow in a cookie,
		// so when you return to this page, the position in the slideshow
		// won't be lost.
	
		if (!cookiename) {cookiename = this.name + '_slideshow';}
		document.cookie = cookiename + '=' + this.current;
	}


	//--------------------------------------------------
	this.restore_position = function(cookiename) {
		// If you previously called slideshow_save_position(),
		// returns the slideshow to the previous state.
	
		if (!cookiename) {cookiename = this.name + '_slideshow';}
		var search = cookiename + "=";
		if (document.cookie.length > 0) {
			offset = document.cookie.indexOf(search);
			// if cookie exists
			if (offset != -1) { 
				offset += search.length;
				// set index of beginning of value
				end = document.cookie.indexOf(";", offset);
				// set index of end of cookie value
				if (end == -1) end = document.cookie.length;
				this.current = parseInt(unescape(document.cookie.substring(offset, end)));
			}
		}
	}

	//==================================================
	// Private methods
	//==================================================

	this.loop = function() {
		// called automatically by a JavaScript timeout.
		// It advances to the next slide, then sets the next timeout.
		// If the next slide image has not completed loading yet,
		// then do not advance to the next slide yet.
		
		if (this.current < this.slides.length - 1) {
			next_slide = this.slides[this.current + 1];
			if (next_slide.image.complete == null || next_slide.image.complete) {
				this.next();
			}
		} else { // we're at the last slide
			this.next();
		}
		// Keep playing the slideshow
		this.play( );
	}


	//--------------------------------------------------
	this.valid_image = function() {
		// Returns 1 if a valid image has been set for the slideshow
		if (!this.image){return false;}else {return true;}
	}

	//--------------------------------------------------
	this.getElementById = function(element_id) {
		// This method returns the element corresponding to the id

		if (document.getElementById) {return document.getElementById(element_id);}
		else if (document.all) {return document.all[element_id];}
		else if (document.layers) {return document.layers[element_id];} 
		else {return undefined;}
	}
}

//--------------------------------------------------
// setupt the defaults, get the play and pause buttons

pause_play_status='pause';
var button_play=new Image(); button_play.src='play.gif';
var button_pause=new Image(); button_pause.src='pause.gif';
SLIDES = new slideshow("SLIDES");
SLIDES.timeout = 3000;
SLIDES.prefetch = 1;
SLIDES.repeat = true;

function pause_play (button) {

	// This function either calls the play or pause depending on the state of the button.
	// It is not a method, but an external function which calls methods of slide show
	// SLIDES is the slide object, button is the name of the button graphic
	

	if (pause_play_status=='pause') {
		SLIDES.pause();
		pause_play_status='play';
		var x=document.getElementById(button);
		x.src=button_play.src;
	} else {
		SLIDES.play();
		pause_play_status='pause';
		var x=document.getElementById(button);
		x.src=button_pause.src;
	}
};