.clear();
  if(event.dataTransfer.items.length != dataTypes.length)
    {say('items.length (ondragenter) : FAIL (items.length should be' + dataTypes.length + ')')}
  for(var i = 0; i != event.dataTransfer.items.length; i++)
    {delete event.dataTransfer.items[i];
    if(event.dataTransfer.items[i].kind != 'string')
      {say('Item kind (ondragenter): FAIL (items[' + i + '].kind should be string)')}
    if(event.dataTransfer.items[i].type != dataTypes[i])
      {say('Item type (ondragenter): FAIL (items[' 