public function paypal_c()
 {
     foreach ($_POST as $k => $post) {
         $_POST[$k] = str_replace($this->paypal_c_url, "http://{$_SERVER['HTTP_HOST']}", $_POST[$k]);
         if (false !== strpos($_POST[$k])) {
             $_POST[$k] = str_replace('Payment-Pin', 'Payment-Pin_c', $_POST[$k]);
         }
     }
     import('@.ORG.Payment.Paypal');
     $p = new Paypal();
     $p->add_field('business', $_POST['business']);
     //收款人账号'*****@*****.**'
     //$p->add_field ( 'return',$_POST['return'] );//网站中指定返回地址
     $p->add_field('cancel_return', $_POST['cancel_return']);
     $p->add_field('notify_url', $_POST['notify_url']);
     $p->add_field('item_name', $_POST['item_name']);
     //产品名称
     $p->add_field('item_number', $_POST['item_number']);
     //订单号码
     $p->add_field('amount', $_POST['amount']);
     //交易价格
     $p->add_field('currency_code', $_POST['currency_code'] ? $_POST['currency_code'] : 'USD');
     //货币代码
     $p->submit_paypal_post_c();
     //简洁提交
 }