如何在PHP中添加post操作

我正在使用我在网上找到的捕获系统来保护我的表单。我过去曾多次使用它，但一直使用mailto函数，这次我需要使用一个动作url，不知道语法

这是验证码脚本

<?php 
session_start();
if( isset($_POST['submit'])) {
   if( $_SESSION['security_code'] == $_POST['security_code'] && !empty($_SESSION['security_code'] ) ) {
        // Insert you code for processing the form here, e.g emailing the submission, entering it into a database. 
        action="https://www.salesforce.com/servlet/servlet.WebToLead?encoding=UTF-8" method="POST"
        echo 'Thank you. Your info has been submitted.';
        unset($_SESSION['security_code']);
   } else {
        // Insert your code for showing an error message here
        echo 'Sorry, you have provided an invalid security code';
   }
} else {
?>

它需要提交到

<form action="https://www.salesforce.com/servlet/servlet.WebToLead?encoding=UTF-8" method="POST"><input type="hidden" name="oid" value="XXXXXXXXXXXXXXXX" />

这是为了提交给我的salesforce。