sub change_dboption_true(){

my ( $dbh, $DB ) = @_;
my $option = "single user";
my $switch = "true";
my $sql;
   
    $sql = "use master";
    $$dbh->do($sql) or $app->error($FATAL,"Can't do SQL statement [ $sql ] :: $DBI::errstr"); FAILS HERE

    $sql = "sp_dboption $DB, \"$option\", $switch";
    $$dbh->do($sql) or $app->error($FATAL,"Can't do SQL statement [ $sql ] :: $DBI::errstr");

    $sql = "use $DB";
    $$dbh->do($sql) or $app->error($FATAL,"Can't do SQL statement [ $sql ] :: $DBI::errstr");

    $sql = "checkpoint";
    $$dbh->do($sql) or $app->error($FATAL,"Can't do SQL statement [ $sql ] :: $DBI::errstr");

    $$dbh->disconnect;

}#end change_dboption_true