use WWW::Mechanize;
my $mech = WWW::Mechanize->new( autocheck => 1 );
$mech->agent_alias( 'Windows IE 6' );
$mech->get("https://ecf.nynd.uscourts.gov/doc1/12501815060?pdf_toggle_possible=1&de_seq_num=17732 85&caseid=29430&got_receipt=1");
$mech->form_name('GetPass');
$mech->field(login => "xxx"); #Username
$mech->field(key => "xxx"); #Password
$mech->click();
print $mech->content;