vlad275,
Не используйте в input имя submit и autocomplete="off добавьте кавычки
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title></title>
</head>
<body onload="document.getElementById('post_order_form').submit()">
<form id="post_order_form" action="http://www.bochkavpechatleniy.com/prize/order/135" method="post" autocomplete="off" />
<input type="hidden" name="_submit" value="Заказать" />
<input type="text" name="user_fio" value="" />
<input type="text" name="user_postal_code" value="" />
<input type="text" name="user_area" value="" class="text_full" />
<input type="text" name="user_city" value="" class="text_full" />
<input type="text" name="user_street" value="" />
<input type="text" name="user_bld" value="" />
<input type="text" name="user_sub_bld" value="" />
<input type="text" name="user_flat" value="" />
<input type="hidden" name="action" value="order" />
<input type="hidden" name="delivery_type" value="3" />
</form>
</body>
</html>