php-get在通过代理连接时运行两次

我遇到一个问题，php页面运行两次，但通过代理服务器连接时只运行两次。如果用户没有通过代理进行连接，则此代码运行良好。

如何修复此问题，使其仅运行一次，无论是否通过代理连接

此php代码在Drupal CMS页面中运行，但独立于Drupal。用户通过单击超链接来访问此页面。

是不是我正在使用页眉将用户重定向到另一个页面？

<?php
$userId = 0;
$userId = $_GET["userId"];
$userEmail = 0;
$userEmail = $_GET["userEmail"];
$userName = 0;
$userName = $_GET["userName"];
//connect to the database
$con = mysql_connect("HOSTNAME","USERNAME","PASSWORD");
if (!$con)
  {
  die('Could not connect: ' . mysql_error());
  }
else
{
//echo "Connected.";
//echo "<br>";
}
mysql_select_db("formredirectdata", $con);

$userId = intval($userId);
mysql_query("INSERT INTO webforms
(userid, formisactive, formname, formtitle, shortdesc, confirmationlink) VALUES('$userId', '1', 'Form Name', 'Form Title', 'Short Description', 'Confirmation Link') ") 
or die(mysql_error());  
$newformnum = mysql_insert_id();
$recipientname = 0;
$recipientemail = 0;
$recipientname = "default" . $newformnum;
$recipientemail = $userEmail;
//send to the next script
header('Location: addtriggernewform.php?formnum2=' . $newformnum . '&recipientemail=' . $recipientemail . '&operator=(default)&inputname=(default)&triggervalue=(default)&userName=' . $userName);
?>