#!/user/bin/perl  
use warnings;
use strict;
use WWW::Mechanize;

my $browser = WWW::Mechanize->new;
$browser->get( 'https://registrar.ucdavis.edu/courses/search/index.cfm');
$browser->form_number(3); #Search Form
$browser->select('subject', 'AAS');
$browser->submit();

print $browser->content();