sub check {
local($user, $group) = @_;
$groupSID = `wbinfo -n "$group"`;
$groupSID = substr($groupSID, 0, index($groupSID, ' ') + 1);
chop $groupSID;
$groupGID = `wbinfo -Y "$groupSID"`;
chop $groupGID;
return 'OK' if(`wbinfo -r \Q$user\E` =~ /^$groupGID$/m);
return 'ERR';
}