function slide(src,link,text,target,attr) 
{
  this.src = src;
  this.link = link;
  this.text = text;
  this.target = target;
  this.attr = 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 ) 
{
  this.name = slideshowname;
  this.repeat = true;
  this.prefetch = -1;
  this.image;
  this.textid;
  this.textarea;
  this.timeout = 3000;
  this.slides = new Array();
  this.current = 0;
  this.timeoutid = 0;
  this.add_slide = function(slide) 
  {
    var i = this.slides.length;
    if (this.prefetch == -1) 
    {
      slide.load();
    }
    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() 
  {
    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 slide = this.slides[ this.current ];
    slide.load();
    this.image.src = slide.image.src;
    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.next = function() 
  {
    if (this.current < this.slides.length - 1) 
    {
      this.current++;
    } 
    else if (this.repeat) {
      this.current = 0;
    }
    this.update();
  }

  this.previous = function() 
  {
    if (this.current > 0) {
      this.current--;
    } 
    else if (this.repeat) 
    {
      this.current = this.slides.length - 1;
    }
    this.update();
  }

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

  this.get_all_text = function(before_slide, after_slide) 
  {
    all_text = "";
    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) 
  {
    if (!text) 
    {
      text = this.slides[ this.current ].text;
    }
    if (this.textarea && typeof this.textarea.value != 'undefined') 
    {
      this.textarea.value = text;
    }
    if (this.textid) 
    {

      r = this.getElementById(this.textid);
      if (!r) { return false; }
      if (typeof r.innerHTML == 'undefined') { return false; }

      r.innerHTML = text;
    }
  }
  
  this.loop = function() 
  {
    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 
    {
      this.next();
    }
    this.play( );
  }

  this.valid_image = function() 
  {
    if (!this.image)
    {
      return false;
    }
    else 
    {
      return true;
    }
  }

  this.getElementById = function(element_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;
    }
  }
}