jQuery AJAX脚本在Firefox中不起作用

我不明白为什么这个脚本在Firefox中不起作用。而且，即使我的ajax_loadmore.php输出FALSE，它仍然进行AJAX调用（在Chrome中）。

var request;
$(window).scroll(function () {
   if ($(window).scrollTop() == $(document).height() - $(window).height() ) {
      var ID = $('.stbody:last').attr('id').match(/stbody('d+)/)[1];
      $('#loader').show();
      if(request) {
        return
      }
      request = $.ajax({
        type: 'GET',
        url: "ajax_loadmore.php?lCom="+ID,
        success: function(result) {
            if(result!='FALSE') {
                $('#loader').hide();
                $('#moreComments').append(result);
                $(".oembed").oembed(null, {
                    embedMethod: "fill",
                    maxWidth: 700,
                    maxHeight: 600
                });
                request = null;
            } else {
                $('#loader').hide();
                $('#moreComments').html('<center><p>Slut på inlägg</p></center>');
                request = null;
            }
        }
      }); 
   }
});

ajax_loadmore.php代码：

<?php
if($_GET['lCom']) {
  include_once 'core/init.php';
  protect_page();
  include_once 'includes/db.php';
  include_once 'includes/functions.php';
  include_once 'includes/tolink.php';
  include_once 'includes/time_stamp.php';
  include_once 'session.php';
  $lCom = $_GET['lCom'];
  $Wall = new Wall_Updates();
  $updatesarray=$Wall->Updates_more($uid,$lCom);
  if(!empty($updatesarray)) {
    foreach($updatesarray as $data) {
      $msg_id=$data['msg_id'];
      $orimessage=$data['message'];
      $message=tolink(htmlspecialchars(nl2br($data['message'])));
      $time=$data['created'];
      $username=$data['username'];
      $uid=$data['uid_fk'];
      $face=get_profile_pic($uid,'small');
      $face2=get_profile_pic($session_user_id,'mini'); 
      $commentsarray=$Wall->Comments($msg_id);
      ?>
        //HTMLSTUFF HERE.. 
      <?php
      }
  } else { echo 'FALSE'; }
} else { die('du ska inte vara här..'); }
?>