eval {
    $dbh->nsql( "begin transaction" );
    $dbh->nsql( <update query 1> );
    die "problem with query 1" if $status == 0;
    .
    .
    $dbh->nsql( <update qurey n> ); 
    die "problem with query n" if $status == 0;
};

if( $@ ) {
   $dbh->nsql( "rollback" );
} else {
   $dbh->nsql( "commit" );
}