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

  this.hotlink = function() {
    if (this.target) {
      if (this.attr) {
        window.open(this.link, this.target, this.attr);
        } else {
        window.open(this.link, this.target);
      }
    } 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 = 7000;
  this.slides = new Array();
  this.current = 0;
  this.timeoutid = 0;


  this.add_slide = function(slide) {
    if (!document.images) { return; }
    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;
    }
    this.timeoutid = setTimeout( this.name + ".loop()", this.timeout);
  }
  this.pause = function() {
    if (this.timeoutid != 0)
    {
      clearTimeout(this.timeoutid);
      this.timeoutid = 0;
    }
  }


  this.update = function() {
    if (! this.valid_image()) { return; }
    this.slides[ this.current ].load();
    this.image.src = this.slides[ this.current ].image.src;
    this.display_text();
    if (this.prefetch > 0) {
      for (i = this.current + 1;
           i <= (this.current + this.prefetch) && i < this.slides.length;
           i++) {
        this.slides[i].load();
      }
    }
  }


  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.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) {
      this.textarea.value = text;
    }

    if (this.textid) {
      if (!document.getElementById){ return false; }
  
      r = document.getElementById(this.textid);
      if (!r){ return false; }
      r.innerHTML = text;
    }
  }


  this.hotlink = function() {
    this.slides[ this.current ].hotlink();
  }

  this.save_position = function(cookiename) {
    if (!cookiename) {
      cookiename = this.name + '_slideshow';
    }
    document.cookie = cookiename + '=' + this.current;
  }


  this.restore_position = function(cookiename) {
    if (!cookiename) {
      cookiename = this.name + '_slideshow';
    }
    var search = cookiename + "=";
    if (document.cookie.length > 0) {
      offset = document.cookie.indexOf(search);
      if (offset != -1) { 
        offset += search.length;
        end = document.cookie.indexOf(";", offset);
        if (end == -1) end = document.cookie.length;
        this.current = parseInt(unescape(document.cookie.substring(offset, end)));
        }
     }
  }


  this.noscript = function() {
    $html = "\n";
    for (i=0; i < this.slides.length; i++) {
  
      slide = this.slides[i];
  
      $html += '<P>';
  
      if (slide.link) {
        $html += '<a href="' + slide.link + '">';
      }
  
      $html += '<img src="' + slide.src + '" ALT="slideshow image">';
  
      if (slide.link) {
        $html += "<\/a>";
      }
  
      if (slide.text) {
        $html += "<BR>\n" + slide.text;
      }
  
      $html += "<\/P>" + "\n\n";
    }
  
    $html = $html.replace(/\&/g, "&amp;" );
    $html = $html.replace(/</g, "&lt;" );
    $html = $html.replace(/>/g, "&gt;" );
  
    return('<pre>' + $html + '</pre>');
  }



  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)
    {
      this.pause;
  
      window.status = "Error: slideshow image not initialized for " + this.name;
          
      return 0;
    }
    else {
      return 1;
    }
  }

  this.set_image = function(imageobject) {
    if (!document.images)
      return;
    this.image = imageobject;
  }


  this.set_textarea = function(textareaobject) {
    this.textarea = textareaobject;
    this.display_text();
  }


  this.set_textid = function(textidstr) {
    this.textid = textidstr;
    this.display_text();
  }
}