#!/usr/local/bin/perl 

use strict;
use warnings;

use WWW::Mechanize::Firefox;

use 5.010;

my $mech = WWW::Mechanize::Firefox->new(
  autoclose => 0,
);

my $url =
q(https://selfservice.mypurdue.purdue.edu/prod/bwckctlg.p_disp_dyn_ctlg?);

$mech->get($url);

say q(got url);

say q(choose term);
$mech->form_number(1);
$mech->field('cat_term_in', '201220');
$mech->submit();

say q(choose subject);
$mech->form_number(1);
$mech->select('sel_subj', ['AAE']);
$mech->submit();

say $mech->content();

##</code><code>##

got url
choose term
choose subject
2 elements found for './/*[(local-name(.)="input" or local-name(.)="select" or local-name(.)="textarea") and @name="sel_subj"]' at ./get_course_descriptions2.pl line 28

##</code><code>##

<FORM ACTION="/prod/bwckctlg.p_display_courses" METHOD="POST">
<INPUT TYPE="hidden" NAME="term_in" VALUE="201220">
<INPUT TYPE="hidden" NAME="sel_subj" VALUE="dummy">
^^^^^ Relavant Hidden Input Type
<SNIPPED HTML>

vvvvvvvvv Relevant Select Name
<SELECT NAME="sel_subj" SIZE="3" MULTIPLE ID="subj_id">
<OPTION VALUE="AAE">AAE-Aero & Astro Engineering