I am writing some code that reads the forms and processes the information on the fly. I've found that using HTML::Form works really well for me. This is the form that has radio buttons, and drop-down menus and a single submit button

@requestForms = HTML::Form->parse( $response->content, $response->base
+ );
#Multiple forms on the page, The first one is always ignored
$requestForms[1]->value('radiobutton' => 'name of radio button I want 
+selected');
@options = $requestForms[1]->find_input('name of drop-down menu')->pos
+sible_values();
#Select the first item in the list
$requestForms[1]->value( 'name of drop-down menu' => $options[1] );
#There is always only 1 button, if there are more than 1 then put the 
+name as an argument to click.
$response = $userAgent->request($requestForms[1]->click( ));
[download]

Hope this helps!