function cta_fadein(num)
{
  var photo = $('photo'+num);
  photo.setOpacity(0.75);
  //new Effect.Appear(photo, { duration: 0.3, queue: 'end' });
}

function cta_fadeout(num)
{
  var photo = $('photo'+num);
  photo.setOpacity(1.0);
  //new Effect.Fade(photo, { duration: 0.3, queue: 'end' });  
}