var num_photos = 15;
var num = 0;

var order = new Array();
for(var i=0; i<num_photos; i++)
{
  order.push(i);
}
order.sort(randOrd);

function next_photo() {
  if(num == (num_photos-1)) return;
  num = num+1
  var elt = document.getElementById("photo");
  elt.src = "wp-content/uploads/favorites/fav_"+order[num]+".jpg";
}

function prev_photo() {
  if(num == 0) return;
  num = num-1
  var elt = document.getElementById("photo");
  elt.src = "wp-content/uploads/favorites/fav_"+order[num]+".jpg";
}

function randOrd()
{
  return (Math.round(Math.random())-0.5); 
}

function first_fav()
{
  var elt = document.getElementById("photo");
  elt.src = "wp-content/uploads/favorites/fav_"+order[num]+".jpg";
}