sub getsqlvalue {
    my ($dbh,$sqlstatement)= @_;
    my $sth = $dbh->prepare($sqlstatement)
    $sth->execute || die "MySQL execute failed";
    my $rows = $sth->fetchall_arrayref;
    $sth->finish();

    return ( ref( $rows ) eq 'ARRAY' and @$rows ) ? $$rows[0][0] : undef;
}