function pictureGallery(nr) {	//
  next = nr+1;
  previous = nr-1;

  if(previous>=0)
  {
   document.getElementById('previous-o').innerHTML = '<a href="#" onclick="pictureGallery(' + previous + ')">&#171;</a>';
   document.getElementById('previous-u').innerHTML = '<a href="#" onclick="pictureGallery(' + previous + ')">&#171;</a>';
  }
  else
  {
   document.getElementById('previous-o').innerHTML = '';
   document.getElementById('previous-u').innerHTML = '';
  }

  if(next<arr_images.length)
  {
    document.getElementById('next-o').innerHTML = '<a href="#" onclick="pictureGallery(' + next + ')">&#187;</a>';
    document.getElementById('next-u').innerHTML = '<a href="#" onclick="pictureGallery(' + next + ')">&#187;</a>';
  }
    else
  {
   document.getElementById('next-o').innerHTML = '';
   document.getElementById('next-u').innerHTML = '';
  }
  document.getElementById('image').innerHTML = '<img src="' + arr_images[nr]['path'] + '"/>';
  document.getElementById('desc').innerHTML = arr_images[nr]['desc'];

}