function handleRequest(request, response) { response.setHeader("Cache-Control", "no-cache", false); response.setHeader("Content-Type", "text/javascript", false); response.write("ok(asyncRan, 'Async script should have run first.'); firstRan = true;"); response.processAsync(); var timer = Components.classes["@mozilla.org/timer;1"] .createInstance(Components.interfaces.nsITimer); timer.initWithCallback(function() { response.finish(); }, 200, Components.interfaces.nsITimer.TYPE_ONE_SHOT); }