var currentTagTokens = currentTags.split( "," );
  var existingTags = "";

  for ( var i = 0; i < currentTagTokens.length; i++ )
  {
    existingTags = existingTags + currentTagTokens[ i ] + ", ";
  }

  // Remove the trailing ", " from existingTags
  existingTags = existingTags.substring( 0, existingTags.length - 3 );