function slide(src, link, target, text, attr) {
  this.src = src;
  this.text = (typeof text == 'undefined') ? "" : unescape(text);
  this.link = (typeof link == 'undefined') ? "" : link;
  this.target = (typeof target == 'undefined') ? "" : target;
  this.attr = (typeof attr == 'undefined') ? "" : attr;

  if (document.images) 
  {
    this.image = new Image();
  }
  this.loaded = false;

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

  this.hotlink = function() {
    var mywindow;
    if (!this.link)
    { 
    	return;
    }

    if (this.target) 
    {
      if (this.attr) 
      {
        mywindow = window.open(this.link, this.target, this.attr);
  
      } 
      else 
      {
        mywindow = window.open(this.link, this.target);
      }

      if (mywindow && mywindow.focus) mywindow.focus();

    } 
    else 
    {
      location.href = this.link;
    }
  }
}



function slideshow( slideshowname, mainurl ) {
  this.name = slideshowname;
  this.url = mainurl;

  this.repeat = true;
  this.prefetch = -1;

  this.timeout = 3000;
  this.slides = new Array();
  this.current = 0;
  this.timeoutid = 0;

	this.add_slide = function(slide, times) {

		counter = (typeof times == 'undefined') ? 1 : times;

	//if : (http:, file: etc) is specified in source do not add mainurl
		if (slide.src.indexOf(':') == -1)
		{
			slide.src = this.url + slide.src;
		}

		if (this.prefetch == -1) 
		{
			slide.load();
		}

		for (count = 0; count < counter; count++)
		{
			var i = this.slides.length;

			this.slides[i] = slide;
		}
	}

  //--------------------------------------------------
  this.play = function(timeout) {
    
    this.pause();
  
    
    if (timeout) {
      this.timeout = timeout;
    }
  
        if (typeof this.slides[ this.current ].timeout != 'undefined') {
      timeout = this.slides[ this.current ].timeout;
    } else {
      timeout = this.timeout;
    }

    this.timeoutid = setTimeout( this.name + ".loop()", timeout);
  }

  //--------------------------------------------------
  this.pause = function() {
	  //alert("pause");
	if (this.timeoutid != 0) {
      clearTimeout(this.timeoutid);
      this.timeoutid = 0;

    }
  }

  //--------------------------------------------------
  this.update = function() {
	 if (! this.valid_image()) { return; }
  
    if (typeof this.pre_update_hook == 'function') {
      this.pre_update_hook();
    }

	var s = this.slides[ this.current ];
    var dofilter = false;
    if (this.image &&
        typeof this.image.filters != 'undefined' &&
        typeof this.image.filters[0] != 'undefined') {

      dofilter = true;

    }

    s.load();
    if (dofilter) {

      if (s.filter &&
          this.image.style &&
          this.image.style.filter) {

        this.image.style.filter = s.filter;

      }
      this.image.filters[0].Apply();
    }

    this.image.src = s.image.src;
    if (dofilter) {
      this.image.filters[0].Play();
    }

    this.display_text();

    if (typeof this.post_update_hook == 'function') {
      this.post_update_hook();
    }

    if (this.prefetch > 0) {

      var next, prev, count;

      next = this.current;
      prev = this.current;
      count = 0;
      do {
        if (++next >= this.slides.length) next = 0;
        if (--prev < 0) prev = this.slides.length - 1;

        this.slides[next].load();
        this.slides[prev].load();

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

  this.goto_slide = function(n) {
    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(include_current) {
    var i;
    if (this.slides.length > 1) {

      do {
        i = Math.floor(Math.random()*this.slides.length);
      } while (i == this.current);

      this.goto_slide(i);
    }
  }


  this.next = function() {
	  this.pause();
    if (this.current < this.slides.length - 1) {
		this.current++;
		this.update();
    } 
	else
	{
		this.current = 0;
	    this.update();
    }

  }


	this.shuffle = function()
	{
		var i, i2, slides_copy, slides_randomized, tmp;
		slides_copy = new Array();
		for (i = 0; i < this.slides.length; i++)
		{
			slides_copy[i] = this.slides[i];
		}
		tmp = this.slides.length;

		slides_randomized = new Array();


		do
		{
			i = Math.floor(Math.random()*tmp);
			slides_randomized[ slides_randomized.length ] =
			slides_copy[i];
			for (i2 = i + 1; i2 < tmp; i2++)
			{
				slides_copy[i2 - 1] = slides_copy[i2];
			}
			tmp--;

		} while (tmp);
		this.slides = slides_randomized;
	}


  this.get_text = function() {
  
    return(this.slides[ this.current ].text);
  }

	this.get_weight = function()
	{
		return(this.slides[this.current].weight);
	}



  //--------------------------------------------------
  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;
    }



    // If a textarea has been specified,
    // then change the text displayed in it
    if (this.textarea && typeof this.textarea.value != 'undefined') {
      this.textarea.value = text;
    }

    // If a text id has been specified,
    // then 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; }
			r.innerHTML = text;
		}
		return true;
	}


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




  //==================================================
  // 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.

		// start at beginning if we reached the end
		if (this.current == this.slides.length - 1)
		{
			this.current = -1;
		}

		next_slide = this.slides[this.current + 1];
		// Make sure the next slide image has finished loading
		if (next_slide.image.complete == null || next_slide.image.complete)
		{
			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;
    }
  }
  

}