
function initSlideshow() {

	document.getElementById("slideshow").onmouseover = function() {slides.pause();};
	document.getElementById("slideshow").onmouseout = function() {slides.play();};


	if (document.images) {
		slides.image = document.images.slidesimg;
		slides.update();
		slides.play();
	}

}






// There are two objects defined in this file:
// "slide" - contains all the information for a single slide
// "slideshow" - consists of multiple slide objects and runs the slideshow

//==================================================
// slide object
//==================================================
function slide(src) {
  // 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
  this.src = src;


  // 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;
    }
  }


}

//==================================================
// 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
  // (required if you want your slideshow to auto-play)
  // For example, "slides1"
  this.name = slideshowname;

  // When we reach the last slide, should we loop around to start the
  // slideshow again?
  this.repeat = true;

  // Number of images to pre-fetch.
  // -1 = preload all images.
  //  0 = load each image is it is used.
  //  n = pre-fetch n images ahead of the current image.
  // I recommend preloading all images unless you have large
  // images, or a large amount of images.
  this.prefetch = -1;

  // IMAGE element on your HTML page.
  // For example, document.images.slides1img
  this.image;



  // Milliseconds to pause between slides.
  // Individual slides can override this.
  this.timeout = 4000;


  // These are private variables
  this.slides = new Array();
  this.current = 0;
  this.timeoutid = 0;

  //--------------------------------------------------
  // Public methods
  //--------------------------------------------------
  this.add_slide = function(slide) {
    // Add a slide to the slideshow.
    // For 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) {
    // This method implements the automatically running slideshow.
    // If you specify the "timeout" argument, then a new default
    // timeout will be set for the slideshow.
  
    // Make sure we're not already playing
    this.pause();
  
    // If the timeout argument was specified (optional)
    // then 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') {
      timeout = this.slides[ this.current ].timeout;
    } else {
      timeout = this.timeout;
    }

    // After the timeout, call this.loop()
    this.timeoutid = setTimeout( this.name + ".loop()", timeout);
  }

  //--------------------------------------------------
  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; }

    // Convenience variable for the current slide
    var slide = this.slides[ this.current ];

    // Load the slide image if necessary
    slide.load();
  

    // 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;

    }


    // 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.
    this.image.src = slide.image.src;

    // Play the image transition filters
    if (dofilter) {
      this.image.filters[0].Play();
    }




    // Do we need to pre-fetch images?
    if (this.prefetch > 0) {

      var next, count;

      // Pre-fetch the next slide image(s)
      next = this.current;
      count = 0;
      do {

        // Get the next slide number
        // Loop past the ends of the slideshow if necessary
        if (++next >= this.slides.length) next = 0;

        // Preload the slide image
        this.slides[next].load();

        // Keep going until we have fetched
        // the designated number of slides

      } while (++count < this.prefetch);
    }
  }


  //--------------------------------------------------
  this.next = function() {
    // This method advances to the next slide.

    // Increment the image number
    if (this.current < this.slides.length - 1) {
      this.current++;
    } else if (this.repeat) {
      this.current = 0;
    }

    this.update();
  }








  //==================================================
  // Private methods
  //==================================================

  //--------------------------------------------------
  this.loop = function() {
    // This method is for internal use only.
    // This method gets 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.

    // Make sure the next slide image has finished loading
    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;
    }
  }
  

}
