public static function isValid($uoid)
	{
		$uoid = explode(UOID::SEPARATOR, $uoid);
		
		if(count($uoid) != 2)
			return false;
		
		// check GID
		if(!GID::isValid($uoid[0]))
			return false;
		
		// check id
		if(!preg_match("/^[a-zA-Z0-9]+$/", $uoid[1]) || strlen($uoid[1]) != 16)
		{
			return false;
		}
		
		return true;
	}