ajax post-request, longer strings are not transmitted

ajax post-request, longer strings are not transmitted

Hey,
i try to transmit some text from a html-textarea by an post request. When the content of the textarea exceeds roundabout 500 characters (this isn't a very long string...) then only an empty string ist transmitted. I already checked the server-settings, they seem to be ok! When you take a look at the code, then you see two forms, form "mailform2" sinple transmit the content with a submit button without ajax. Then everything is fine and even veeery long strings are transmitted, so i believe it isn't a serverside problem. But the same with "mailform1" and ajax works only with strings less then 500 chars. Has anybody an idea, i stuck on this problem since days...

Thanks for any help...

<html>
  <head>
    <script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.3.2/jquery.min.js"></script>
    <script type="text/javascript">

      function ajaxSendTest()
      {
        var strUrl = 'someserver/ajaxTest.php';
        var strFormVars = $("#mailform1").serialize();
        
        alert(strFormVars); //Here everything is fine...
       
        $.ajax
        ({
          url: strUrl,
          method: 'post',
          data: strFormVars,
          success: ok,
          error: nok
        });
      }
      function ok(request)
      {
        alert(request);
      }
      function nok(error)
      {
        alert(error);
      }
    </script>
  </head>
  
  </body>
  
    <form id="mailform1">
      <p><textarea name="nachricht" id="nachricht" cols="50" rows="40"></textarea></p>
      <input type="button" value=" Absenden "  onclick="ajaxSendTest()">
    </form>
    
    <form id="mailform2" action="someserver/ajaxTest.php" method="POST">
      <p><textarea name="nachricht" id="nachricht" cols="50" rows="40"></textarea></p>
      <input type="submit" value=" Absenden ">
    </form> 
    
  </body>
</html>