my $sth = $dbh->prepare('SELECT * FROM charge WHERE cpt = ? AND col2 = ? ')
                or die "Couldn't prepare statement: " . $dbh->errstr;
print "Enter cpt code> ";
my $cptcode = <>;
chomp $cptcode;
if ( defined $cptcode && $cptcode ne '') { 
    print "Enter col2 code> ";
    my $col2 = <>; 
    chomp $col2;
    if (defined $col2 && $col2 ne '') { 
        $sth->execute($cptcode,$col2) # Execute the query
                        or die "Couldn't execute statement: " . $sth->errstr;

        ....
        } # col2 
    } # cpt