As Eliya already stated, you weren't accurately creating a hidden field.

It's also important to note that if you want to capture the previous value of OldBugText, then you're going to have to save it in a temporary variable since you want to overwrite it each time as well. Something like the following is probably what you're aiming for:

#!/usr/bin/perl -wT

use CGI;
use CGI::Carp qw(fatalsToBrowser warningsToBrowser);

use strict;
use warnings;

my $q = CGI->new;

my $prev = $q->param('OldBugText'); $prev = '' if ! defined $prev;
$q->param('OldBugText' => $q->param('BugText'));

print $q->header;
print $q->start_html("Problem demo");
print "<h1>Problem demo</h1>\n";
print $q->start_form;
print $q->hidden(-name => "OldBugText");
print "<p>Previous Value: ", $q->escapeHTML($prev), "</p>";
print "<p>", $q->textarea(
    -name    => 'BugText',
    -value   => "Example Text",
    -rows    => 10,
    -columns => 40
), "</p>";
print "<p>", $q->submit('Action', 'Submit'), "</p>";
print $q->end_form;
print "<hr>\n";
print $q->end_html;

1;

__END__

[download]

In reply to Re: CGI: retaining textarea contents in hidden field by wind
in thread CGI: retaining textarea contents in hidden field by davies

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.