# html
# Note that if the user selects the checkbox, the value is 'on'
<tr><td>I'm logging in from home</td><td><input type="checkbox" name="place"></td></tr>

# cgi
use strict;
use CGI qw(:cgi);
use Data::Dumper;
my $place = seewhatsthere(
  data     => param('place'),
  field    => 'Place',
);

sub seewhatsthere {
  my %hash = @_;
  html_start();
  print Dumper(%hash);
  exit(0);
}

##</code><code>##

# Dumped
$VAR1 = 'Place'; $VAR2 = undef; $VAR3 = 'data'; $VAR4 = 'field'; 

##</code><code>##

# Dumped
$VAR1 = 'data'; $VAR2 = 'on'; $VAR3 = 'field'; $VAR4 = 'Place';