Simple Prime Number Test in node.js and express

prime_numbers.js

// 
//	Created by John F. Mercer on Monday, December 5, 2011
//	[email protected]
//  
//	tested on node 0.6.4 and express 2.5.1
//
var express = require('express'),
    app = express.createServer();

app.use(express.logger());

var isPrimeNumber = function( number ) {
	if (number == 1 || number == 2) {
		return true;
	}
	for (var i=2;i<number;i++) {
		if (number % i == 0) {
			return false;
		}
	} 
	return true;
}

app.get('/', function(req, res){
    res.send('Hello, Optimus Prime.');
});

app.get('/is_prime_number', 
		function(req, res){
			var number = parseInt( req.param( 'number' ), 10 );    
			if (isNaN(number) || number <= 0) {
				res.send(number + " is not a valid number!  Try again!");
				return;
			}
			if ( isPrimeNumber( number ) ) {
				return res.send( number + ' is prime!' );
			} else {
				return res.send( number + " is not prime." );
			}
		} // end function
);

app.listen(3000);
console.log('Express server started on port %s', app.address().port);