$.fn.slideshow = function(options) {
  var settings = {
    timeout: '2000',
    type: 'sequence'
  }
  if(options)
    $.extend(settings, options);

  this.css('position', 'relative');
  var slides = this.find('img').get();
  for ( var i = 0; i < slides.length; i++ ) {
    $(slides[i]).css('zIndex', slides.length - i).css('position', 'absolute').css('top', '0').css('left', '0');
  }
  if ( settings.type == 'sequence' ) {
    setTimeout(function(){
      $.slideshow.next(slides, settings, 1, 0);
    }, settings.timeout);
  }
  else if ( settings.type == 'random' ) {
    setTimeout(function(){
      do { current = Math.floor ( Math.random ( ) * ( slides.length ) ); } while ( current == 0 )
      $.slideshow.next(slides, settings, current, 0);
    }, settings.timeout);
  }
  else {
    alert('type must either be \'sequence\' or \'random\'');
  }
};
$.slideshow = function() {}
$.slideshow.next = function (slides, settings, current, last) {
  for (var i = 0; i < slides.length; i++) {
    $(slides[i]).css('display', 'none');
  }
  $(slides[last]).css('display', 'block').css('zIndex', '0');
  $(slides[current]).css('zIndex', '1').fadeIn('slow');

  if ( settings.type == 'sequence' ) {
    if ( ( current + 1 ) < slides.length ) {
      current = current + 1;
      last = current - 1;
    }
    else {
      current = 0;
      last = slides.length - 1;
    }
  }
  else if ( settings.type == 'random' ) {
    last = current;
    while (	current == last ) {
      current = Math.floor ( Math.random ( ) * ( slides.length ) );
    }
  }
  else {
    alert('type must either be \'sequence\' or \'random\'');
  }
  setTimeout((function(){$.slideshow.next(slides, settings, current, last);}), settings.timeout);
}