$agent->tick($chk_visa,'Visa');

##</code><code>##

use CGI::Pretty qw(:standard);

if (param('chklstCC:0')) {
   print header, param('chklstCC:0');
}
else {
   print header,start_html,start_form,
      checkbox_group(
         -name=>'chklstCC:0',
         -values=>[qw(Visa MasterCard Discover)],
      ),
      submit('go'), end_form, end_html,
   ;
}

##</code><code>##

use WWW::Mechanize;
use Test::More qw(no_plan);

my $bot = WWW::Mechanize->new();
$bot->get('http://localhost/path/to/cgi_script.cgi');

$bot->tick('chklstCC:0','Visa');
$bot->submit;

is( $bot->content(), 'Visa', "Got expected content" );