How to keep a continuous web access while using require("http").createServer

function pageRequest(req, res) {
  res.writeHead(200);
  res.end("Hello World");
}
require("http").createServer(pageRequest).listen(8080); // port 8080

The code like this, when the borad work, it's ok for visiting the pages which the server supply at the very first time. But when I jump for the other websites and visit back via return history of browser, the server stop. I can't visit the server website again. I have to invoke load() for restart then I access the server again.

How to Keep web server working for long time?