/**
 * Writes a media_manager button.
 *
 * @param   string  $directory  The subdirectory to upload the media to.
 * @param   string  $alt        An override for the alt text.
 *
 * @return  void
 *
 * @since   1.5
 */
public static function media_manager($directory = '', $alt = 'JTOOLBAR_UPLOAD')
{
    $bar = Toolbar::getInstance('toolbar');
    // Add an upload button.
    $bar->appendButton('Popup', 'upload', $alt, 'index.php?option=com_media&tmpl=component&task=popupUpload&folder=' . $directory, 800, 520);
}