function showButton() {
  Effect.Appear('homepageButton', { duration: 0.2 });
  new Effect.Move('homepageButton', { x: -10, y: 82, mode: 'absolute',duration: 0.2 });

}; 

function hideButton() {
  Effect.Fade('homepageButton', { duration: 0.2 });
  new Effect.Move('homepageButton', { x: 20, y: 82, mode: 'absolute',duration: 0.2 });
}; 

function createRandomImage() {
  var obj = new Object;
  obj.images = new Array;

  obj.push = function(src) {
    var img = new Image;
    img.src = src;
    this.images.push( img );
    if (!this.src) this.src = img.src;
  };
  obj.shuffle = function() {
    this.shuffled = true;
    this.images.sort( function() {
      return (Math.round(Math.random())-0.5)
    } );
    this.src = this.images[0].src;
  }
  obj.write = function () {
    document.write('<img src="'+this.src+'" alt="" border="0">');
  }
  return obj;
}