in the one instruction I think you ment find this:
Code:
print_form_header('email', 'dosendmail');
construct_hidden_code('test', $vbulletin->GPC['test']);
construct_hidden_code('serializeduser', serialize($vbulletin->GPC['user']));
construct_hidden_code('serializedprofile', serialize($vbulletin->GPC['profile']));
construct_hidden_code('from', $vbulletin->GPC['from']);
construct_hidden_code('subject', $vbulletin->GPC['subject']);
construct_hidden_code('message', $vbulletin->GPC['message']);
construct_hidden_code('startat', $vbulletin->GPC['startat']);
construct_hidden_code('perpage', $vbulletin->GPC['perpage']);
print_submit_row($vbphrase['next_page'], 0);