$dbh=$db->prepare("SELECT nvl(mb_award,0.00),
                          nvl(mb_accept,0.00)
                   FROM Items
                   WHERE itemnum=? AND seller=?
                         AND closef='1'");
$dbh->execute($form{'item'}, $fdnum);
my ($mb_award,$mb_accept) = $dbh->fetchrow_array();

my $mb_amount_disp = $mb_award > 0.00 ? $mb_award : 
                        $mb_accept > 0.00 ? $mb_accept :
                           0.00; # Assume you have negative values

##</code><code>##

use strict;
use DBI;
use DBD::Oracle qw(:ora_types);

# Connect as Oracle
$ENV{ORACLE_HOME}='/users/oracle/OraHome1';
my $dbh=DBI->connect("dbi:Oracle:MyDatabase","username","password");

# Select the some columns from the database
my $sth = $dbh->prepare("select a as Alias, b as Bob
                         from MyTable
                         where c=?");
$sth->execute("Some Value");

# One convenient method is to use a hash reference
while (my $res = $sth->fetchrow_hashref())
{
    # You can refer to values using the name of the column/alias
    # for example...
    my $alias = $res->{Alias};
    my $bob = $res->{Bob};
    ....
}

$sth->finish;
$dbh->disconnect();