use an existing helper file instead of support/echo.php 
diff --git a/XMLHttpRequest/send-sync-no-response-event-loadend.htm b/XMLHttpRequest/send-sync-no-response-event-loadend.htm index 7e468ad..b78d064 100644 --- a/XMLHttpRequest/send-sync-no-response-event-loadend.htm +++ b/XMLHttpRequest/send-sync-no-response-event-loadend.htm 
@@ -22,7 +22,7 @@  pass = true;   };    - xhr.open("POST", "./support/echo.php", false);  + xhr.open("POST", "./resources/content.php", false);   xhr.send();     assert_equals(xhr.response, "");