#!/usr/bin/perl -Tw

use strict;
use CGI qw(:standard);
use DBI;

# connect to the database
my $dbh = DBI->connect(
   qw(DBI:mysql:database:host user pass),
) or die $DBI::errstr;

# prepare the SQL statement
my $sth = $dbh->prepare('
   select foo from baz
   where bar = ?
') or die "prepare failed";

# feed the SQL statement the criteria
$sth->execute(8) or die "execute failed";

# get an array of the fetched row - since
# we are only grabbing one field ...
my @row = $sth->fetchrow_array(); 

# we will store it in a scalar
my $field = $row[0];

# print the HTML
print header,
   start_html,start_form,
   textfield(-name=>'foo',-value=>$field),
   end_form,end_html,

# clean up
$sth->finish;
$dbh->disconnect;
[download]

(update - added shebang line to include taint option)

jeffa

L-LL-L--L-LL-L--L-LL-L--
-R--R-RR-R--R-RR-R--R-RR
B--B--B--B--B--B--B--B--
H---H---H---H---H---H---
(the triplet paradiddle with high-hat)

Apart from use-ing strict and warnings - which you certainly do, I'm sure - you should look at CGI and DBI.

As for populating the fields in the same form, it seems to me that you'll have to put the script into the file with the form and then have it call itself.

--cs

There are nights when the wolves are silent and only the moon howls. - George Carlin