function ProjectThumbnailMouseOver(idx) {
  document.images['ProjectThumbnail' + idx].src = 'images/sm/' + idx + 'over.jpg';
}

function ProjectThumbnailMouseOut(idx) {
  if(idx == CurrentThumbnailIdx)
    return;
  document.images['ProjectThumbnail' + idx].src = 'images/sm/' + idx + '.jpg';
}

CurrentThumbnailIdx = 1;
function ProjectThumbnailClick(idx) {

   if(idx != CurrentThumbnailIdx) {
      // Unhighlight current thumbnail.
      document.images['ProjectThumbnail' + CurrentThumbnailIdx].src = 'images/sm/' + CurrentThumbnailIdx + '.jpg';
   }

   document.images['ProjectImage'].src = 'images/lg/' + idx + '.jpg';

   CurrentThumbnailIdx = idx;
}