I've a linux server (ubuntu) and installed node.js.

My script: webserver.js:

```
var http = require('http');
http.createServer(function (req, res) {
    res.writeHead(200, {'Content-Type': 'text/plain'});
    res.end('Hello World\n');
}).listen(80);
console.log('Server is running');

```

I'm connecting to the server with putty starting the server script:
node webserver.js

It works. But If I close the terminal, the webserver is terminated. How can I solve this?