HTML / PHP表单在添加更多输入字段时给了我500个内部服务器错误 - html/php form gives me 500 internal server error when adding more input fields

嗨，我的php和html表单有问题。我正在尝试做的只是获取一个包含 7 个输入字段的表单，其中 6 个是输入字段或文本区域，一个是复选框。我有一个隐藏字段，前 3 个框隐藏字段是名字和消息。我唯一的问题是当我添加新的输入框时，它会显示 500 错误。我的代码如下：

<?php
// display form if user has not clicked submit
if (!isset($_POST["submit"]))
  {
  ?>
<form method="post" action="<?php echo $_SERVER["PHP_SELF"];?>">
  <input type="hidden" name="subject" value="can you create me an account"><br>
  Message: <textarea rows="10" cols="40" name="message"></textarea><br>
  first <input type="text" name="first_name" >
  <input type="submit" name="submit" value="Submit Feedback">
  </form>
<?php 
  }
else
  // the user has submitted the form
  {
  // Check if the "subject" input field is filled out
  if (isset($_POST["subject"]))
    {
    $subject = $_POST["subject"];
    $message = $_POST["message"];
    $first = $_POST["first_name"];

    $message = wordwrap($message, 70);
    $first = wordwrap($first, 70);
    // send mail
    mail("summat@gmail.com",$subject,$message,$first,"subject: $subject'n");
    echo "Thank you for sending us feedback";

当我添加新的输入框时，我的代码如下所示：

<?php
// display form if user has not clicked submit
if (!isset($_POST["submit"]))
  {
  ?>
<form method="post" action="<?php echo $_SERVER["PHP_SELF"];?>">
   <input type="hidden" name="subject" value="can you create me an account"><br>
   Message: <textarea rows="10" cols="40" name="message"></textarea><br>
   first <input type="text" name="first_name" >
   last <input type="text" name="last_name" >
   <input type="submit" name="submit" value="Submit Feedback">
  </form>
<?php 
  }
else
  // the user has submitted the form
  {
  // Check if the "subject" input field is filled out
  if (isset($_POST["subject"]))
    {
    $subject = $_POST["subject"];
    $message = $_POST["message"];
    $first = $_POST["first_name"];
    $last = $_POST["last_name"];

    $message = wordwrap($message, 70);
    $first = wordwrap($first, 70);
    $last = wordwrap($last, 70);
    // send mail
    mail("summat@gmail.com",$subject,$message,$first,$last,"subject: $subject'n");
    echo "Thank you for sending us feedback";

当我添加它们时，所有内容都会显示在屏幕上，但是当我按提交时，我得到：

500 - 内部服务器错误。您的资源有问题正在寻找，但无法显示。

并且没有提交任何内容。是因为它在发送或大量数据之前超时，还是我只是错过了一些非常基本的东西？

任何帮助将不胜感激。

问题是在第二个示例中，当 mail（）函数接受 5 个变量时，您尝试将 6 个变量传递给它。在此处查看如何传递其他标头的信息。

6 个变量将导致：
警告：mail（）最多需要 5 个参数，其中 6 个在 LINE 上的您的网站中给出

解决方案示例：

    <?php
     //var_dump($_POST);
    if (isset($_POST["subject"]))
        {
        $subject = $_POST["subject"];
        $message = $_POST["message"];
        $first = $_POST["first_name"];
        $last = $_POST["last_name"];
        $name= "$first $last";
    }
        $message = wordwrap($message, 70);
        $first = wordwrap($first, 70);
        $last = wordwrap($last, 70);
        mail("summat@gmail.com",$subject,$message,$name,"subject: $subject'n");
        echo "Thank you for sending us feedback";
      ?>

回答您的回复：
菲律宾语：

 <?php
 //var_dump($_POST);
if (isset($_POST["subject"]))
    {
    $subject = $_POST["subject"];
    $message = $_POST["message"];
    $first = $_POST["first_name"];
    $last = $_POST["last_name"];
    $company = $_POST["company"];
    $email = $_POST["email"];
    $telnr = $_POST["telnr"];
    $description = $_POST["description"];
    $therest = "First name= $first" . "'r'n" . "Last name= $last" . "'r'n" . "Last name= $last" . "'r'n" . "Company= $company" . "'r'n" . "Email= $email" . "'r'n" . "Telnr= $telnr" . "'r'n" . "Description= $description";          
    //echo "$therest <br>";
    $message = wordwrap($message, 70);
    $first = wordwrap($first, 70);
    $last = wordwrap($last, 70);
    mail("Your Email Address Here",$subject,$name,$therest,"subject: $subject'n");
    echo "Thank you for sending us feedback";
}

.HTML

<form method="post" action="<?php echo $_SERVER["PHP_SELF"];?>">
   <input type="hidden" name="subject" value="can you create me an account"><br>
   Message: <textarea rows="10" cols="40" name="message"></textarea><br>
   first <input type="text" name="first_name" ><br>
   last <input type="text" name="last_name" ><br>
   company <input type="text" name="company" ><br>
   email <input type="text" name="email" ><br>
   Telephone number <input type="text" name="telnr" ><br>
   Description <input type="text" name="description" ><br>
   <input type="submit" name="submit" value="Submit Feedback">
  </form>

演示：这里
它会将邮件发送到您在表格中输入的邮件