Update users.php

users.php

 <? require_once($_SERVER["DOCUMENT_ROOT"]."/bitrix/modules/main/include/prolog_before.php");
 
-// $fp = fopen('php://output', 'wb');
-$fp = fopen('users.csv', 'wb');
+header('Content-Type: text/csv');
+header('Content-Disposition: attachment; filename="sample.csv"');
+$fp = fopen('php://output', 'wb');
+// $fp = fopen('users.csv', 'wb');
       $res = Bitrix\Main\UserTable::getList(Array(
          "select"=>Array("*"),         
       ));