我正在尝试将我的文件上传到我服务器上的配置文件/目录,我相信一切都可能正常工作……但是在上传时它认为我的jPEg png和gifs不是正确的文件类型.为什么这样做呢.这有什么不对？我如何解决它？

function change_PRofile_image($user_id,$file_temp,$file_extn) {
$file_path = 'profile/' . substr (md5(time()),10) . '.' . $file_extn;
move_uploaded_file($file_temp,$file_path);
MysqL_query("UPDATE `users` SET `profile` = " . MysqL_real_escape_string($file_path) . "' WHERE `user_id` = " . (int)$user_id);

}

 if (isset($_FILES['profile']) === true) {
    if (empty($_FILES['profile']['name']) === true) {
       echo 'y u no choose file!';
  } else {
       $Allowed = array ('jpg','jpeg','gif','png');
       //this is the part i think may be brocken.
       $file_name = $_FILES['profile']['name'];
       $file_extn = strtolower(end(explode (' . ',$file_name)));
       $file_temp = $_FILES['profile']['tmp_name'];

       if (in_array($file_extn,$allowed) === true) {
        change_profile_image($session_user_id,$file_extn);

        header('Location: dontdelete.PHP');
        exIT();

       }else {
        echo 'y u no jpg or png or gif';       

       }
  }
 }

if (empty($user_data['profile']) === false) {
    echo '<img src"',$user_data['profile'],'" alt="">'; 
}