public static function sanitizeFileName( $filename ) {
		$special_chars = array("?", "[", "]", "/", "\\", "=", "<", ">", ":", ";", ",", "'", "\"", "&", "$", "#", "*", "(", ")", "|", "~", "`", "!", "{", "}", chr(0));
		$filename = str_replace($special_chars, '', $filename);
		$filename = preg_replace('/[\s-]+/', '-', $filename);
		$filename = trim($filename, '.-_');

		return $filename;
		
	}