PHP表單提交HTTP錯誤500

Question

我有一個PHP表單，在我的HTML中有一個提交按鈕。 但是，當我按提交按鈕我的瀏覽器給出了一個錯誤 - > HTTP錯誤500.

我在其他網站上使用相同類型的PHP表單，並在那裏工作正常...任何人看到這裏的問題？

下面代碼片段中的表單和HTML。

<?php 

$lidworden = $_POST['lidworden'] 
$projectsponsoring = $_POST['projectsponsoring']; 
$leo = $_POST['leo']; 
$lion = $_POST['lion']; 
$andere = $_POST['andere']; 
$naam = $_POST['naam']; 
$email = $_POST['email']; 
$bericht = $_POST['bericht']; 

$to = "info@pieterswebdesign.com"; 
$subject = "Leo Club de 4 Ambachten"; 
$body = "Dit is een automatisch bericht gelieve hier niet op te reageren. \n\n $lidworden,$projectsponsoring,$leo,$lion,$andere,$Naam,$Email,$Telefoon,$Bericht"; 

mail($to,$subject,$body); 
header("Location: index.html"); 

exit(); 
?> 

<form id="form" action="send.php" method="POST"> 

    <p id="radiotitle"><span class="bluetxt">Je bent</p> 

     <div id="radiodiv"> 
      <label class="label"> 
       <input type="radio" name="lidworden" value="lidworden" />geïnteresseerd om lid te worden 
      </label> 
      <label class="label"> 
       <input type="radio" name="projectsponsoring" value="projectsponsoring" />geïnteresseerd in projectsponsoring 
      </label> 
      <label class="label"> 
       <input type="radio" name="leo" value="leo"/>een Leo 
      </label> 
      <label class="label"> 
       <input type="radio" name="lion" value="lion"/>een Lion 
      </label> 
      <label class="label"> 
       <input type="radio" name="andere" value="andere"/>andere 
      </label> 
     </div> 

     <div id="textdiv"> 
        <label class="label2">Je naam</label> 
         <input type="text" name="naam" placeholder="Typ hier..." /> 

         <label class="label2">Je e-mailadres</label> 
          <input type="text" name="email" placeholder="Typ hier..." /> 

          <label class="label2">Je bericht</label> 
           <textarea type="text" name="bericht" value="bericht" placeholder="Typ hier..."></textarea> 

      <button type="submit" id="sendbutton"><p>VERSTUUR</p></button> 
     </div> 
    </form>