Hello World! written in nodeJS

hello.js

/* This will display Hello World! on client's web browser.
   The code below will not show up in the source. Only "<strong>Hello World!</strong>" will be visible in source.
*/
var http = require('http');
http.createServer(function (req,res) {
  res.writeHead(200, {'Content-Type:' 'text/html'});
  res.end('<strong>Hello World!</strong>');
}).listen(80, '0.0.0.0');
console.log('Web Server running on port:80 on server ip');