use WWW::Mechanize;

$ua=WWW::Mechanize->new;
$ua->get('http://search.cpan.org');#got a form
warn $ua->forms;
warn $ua->submit;
$ua->get('http://cpan.org');#no forms here
warn $ua->forms;
warn $ua->submit; #dies here

__END__
HTML::Form=HASH(0x1d76ca0) at - line 6.
HTTP::Response=HASH(0x1d77114) at - line 7.
Warning: something's wrong at - line 9.
Can't call method "make_request" on an undefined value at D:/Perl/site/lib/WWW/Mechanize.pm line 1641.