How to run static html file in node.js server

I'm new in node.js, I have learn node.js and express framework

I know how to run server, set router and render html template basicly, but all the tutorial tell render the html by res.send() or render how can I view static file?Like static sample.html:

just like http://127.0.0.1:8000/static.html

my file tree like:

root
|
|---server.js
|---static
    |---static.html

How can I view the static file by setting router?Or use some middleware(Better use express framework)?

Updated: I have try this:

    var express = require('express');
    var app = express.createServer();
    app.get('/', function(req, res){
        res.send('Hello World');
    });
    app.configure(function () {
        app.use(express.static(__dirname + '/static'));
    })

    app.listen(8000);

but it still can not work: tell me:Cannot GET /static/client.html