use Win32::Internet;

my $INET = new Win32::Internet();
my $file = $INET->FetchURL("http://www.seite.de");

use WWW::Mechanize;
use HTML::Form;
my $mech = WWW::Mechanize->new( autocheck => 1 );

my $response = $mech->get( "http://www.seite.de" );

$mech->submit_form(
        form_number => 1,
        fields      => {
            Name123    => 'User',
            PW123    => '12345',
        }
    );
 

open (AUSGABE, ">dump.htm");
print AUSGABE $mech->content;
close (AUSGABE);
        
exit;

$mech->form_number($number)

Selects the numberth form on the page as the target for subsequent calls to field() and click(). Also returns the form that was selected.

$form = $mech->form_number(1);
@inputs = $form->inputs;

foreach $input (@inputs)
        {
        print $input->type.'->'.$input->name."\n";
        }