Node.js __dirname not defined

You are using one underscore while this variable actually has two underscores at the beginning: http://nodejs.org/docs/latest/api/globals.html#globals_dirname

So use

app.use(express.static(__dirname + "/staticFiles"));

instead of

app.use(express.static(_dirname + "/staticFiles"));

use __dirname instead of _dirname (Missing one underscore in your code)