public static function getTempFn() {
		$tempFileName = BROOTPATH . 'temp' . DIRECTORY_SEPARATOR;
		$characters = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';
		$charactersLength = strlen($characters);
		for ($i = 0; $i < 15; $i++) {
			$tempFileName .= $characters[rand(0, $charactersLength - 1)];
		}
		$tempFileName .= '.tmp';
		return $tempFileName;
	}