....<previous code connects to database OK and variable
defined>.......

print "Selecting.... \n";
$sth=$dbh->prepare("SELECT name,address_number from many_address      
                    WHERE name=?
                    AND number=?
                    AND street=? ");
        while ($_=<PA>) {
                ($name,$add,$street)=split(/\|/,$_);
                chomp ($name,$add,$street);
                $name = '' unless defined $name;
                $sth->execute($name,$add,$street);
                #$rec=$sth->dump_results(); ### see results
                @rec = $sth->fetchrow_array();
                if (@rec) { ### check to see if @res is valued
                    print "$name $add,$street --> @rec. \n";
                    $sth=$dbh->prepare("UPDATE many_address
                        SET name=NULL,
                        date_loaded=NULL
                        WHERE name=?
                        AND number=?
                        AND street=? ");
                        $sth->execute($name,$add,$street);
                        print "Clearing $name,$add,$street -->@rec
\n";
                }
                else {
                print " Not available -->@rec is  \n";
                }

        }
close(PA);