var currentVideo = 0;

function nextVideo(videos) {
  currentVideo = (currentVideo + 1)%videos;
  return redraw(videos);
}

function previousVideo(videos) {
  currentVideo = (currentVideo + videos - 1)%videos;
  return redraw(videos);
}

function redraw(videos) {
  for(var i = 0; i < videos; i++) {
	if(currentVideo != i) {
	  document.getElementById('video_'+i).style.display = 'none';
	  document.getElementById('thumb_'+i).style.display = 'none';
	  document.getElementById('desc_'+i).style.display = 'none';
	} else {
	  document.getElementById('video_'+i).style.display = 'block';
	  document.getElementById('thumb_'+i).style.display = 'block';
	  document.getElementById('desc_'+i).style.display = 'block';
	}
  }
  return false;
}

function showTab(n, tabs) {
  for(var i = 1; i <= tabs; i++) {
    if(i == n) {
      document.getElementById('label_'+i).className = 'tabOn';
      document.getElementById('tab_'+i).style.display = 'block';
	  document.getElementById('labelEnd_'+i).src = '/images/tabOnEnd.gif';
	} else {
      document.getElementById('label_'+i).className = 'tabOff';
      document.getElementById('tab_'+i).style.display = 'none';
	  document.getElementById('labelEnd_'+i).src = '/images/tabOffEnd.gif';
    }
  }
}

function openClose(n) {
  var e = document.getElementById('openClose_'+n);
  if(e.style.display == 'block') {
    e.style.display = 'none';
	document.getElementById('openCloseButton_'+n).className = 'openClose';
  } else {
    e.style.display = 'block';
	document.getElementById('openCloseButton_'+n).className = 'openCloseOn';
  }
  return false;
}

function updatetext() {
  var e = document.getElementById('comment');
  if(e.value.length > 512) {
    e.value = e.value.substring(0, 512);
  } else {
    document.getElementById('remaining').innerHTML = (512 - e.value.length)+' characters remaining.';
  }
}