public function decode($str) {

		$str = strtoupper($str);

		$l = strlen($str);
		$n = 0;
		$b = 0;

		$decoded = null;

		for ($i = 0; $i < $l; $i++) {
			$n = $n << 5;
			$n = $n + $this->decodeTable[$str[$i]];
			$b = $b + 5;

			if ($b >= 8) {
				$b = $b - 8;
				$decoded .= chr(($n & (0xFF << $b)) >> $b);
			}
		}

		return $decoded;
	}