function showVideoBox(box_id) 
{
  var box;
  var player;

  box = document.getElementById('videobox'+box_id);
  player = document.getElementById('player'+box_id);
    
  hideVideoBox(1);
  hideVideoBox(2);
  hideVideoBox(3);
  hideVideoBox(4);
  hideVideoBox(5);
        
  if (player != null)
    try {
      player.play();
    }
    catch (e) { }
        
  if (box != null)
    box.style.display = 'block';
}

function hideVideoBox(box_id) 
{
  var box;
  var player;
  
  box = document.getElementById('videobox'+box_id);
  player = document.getElementById('player'+box_id);
        
  if (player != null)
    try {
      player.stop();
    }
    catch (e) { }
                
  if (box != null)
    box.style.display = 'none';
}