function slide(src) {
  this.src = src;
  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;
    }
  }
}
function slideshow( slideshowname ) {
  this.name = slideshowname;
  this.callback = null;
  this.repeat = true;
  this.prefetch = -1;
  this.image;
  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 ];
    var dofilter = false;
    if (this.image &&
        typeof this.image.filters != 'undefined' &&
        typeof this.image.filters[0] != 'undefined') {
      dofilter = true;
    }
    slide.load();
    if (dofilter) {
      if (slide.filter &&
          this.image.style &&
          this.image.style.filter) {
        this.image.style.filter = slide.filter;
      }
      this.image.filters[0].Apply();
    }
    this.image.src = slide.image.src;
    if (dofilter) {
      this.image.filters[0].Play();
    }
    if (typeof this.post_update_hook == 'function') {
      this.post_update_hook();
    }
    if (this.prefetch > 0) {
      var next, count;
      next = this.current;
      count = 0;
      do {
        if (++next >= this.slides.length) next = 0;
        this.slides[next].load();
      } while (++count < this.prefetch);
    }
    if (typeof this.callback == "function") this.callback();
  }
  this.next = function() {
    if (this.current < this.slides.length - 1) {
      this.current++;
    } else if (this.repeat) {
      this.current = 0;
    }
    this.update();
  }
  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() {
  	return (!this.image)?false: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;
    }
  }
}