Elusive button WWW::Mechanize::Firefox

[jjap]

Dear Monks,

I am trying to get the hang of some automation with WWW::Mechanize::Firefox and can get as far as entering data in a form in what I think is a very simple case.

I tried various ways to activate/click/submit the "DECODE" button found on the page but to no avail. Here is my latest effort.

use strict;
use WWW::Mechanize::Firefox;

my $url   = "http://www.decodethis.com";
my $agent = WWW::Mechanize::Firefox->new(
    activate  => 1,
    autoclose => 0,
);

my $sn = "1D7HU18D14J230995";

$agent->get($url);
if ( $agent->success() ) {
    sleep(2);
    print "Retrieved $url\n";
    $agent->form_name('Form');
    $agent->field( 'dnn$ctr373$VINBox$tbVIN' => $sn );
    sleep(2);
    $agent->submit_form( form => $agent->current_form());
}

Any hints would be appreciated.

Best regards!

Update: Corion's suggestion (click instead of submit_form) does the trick.

Also good references suggested by Anonymous to learn on CSS selectors for those, like me, not that familiar with these ways.

Thanks to all.