getting the static directory with nodejs using express?

i have set the static web directory for use in my nodejs app:

app.use express.static(process.cwd(), 'www')

This brings up all the static files like css, images etc, when im in the root it works

http://localhost:8124/

however if i go to somewhere like /tags, it deosnt bring up the static files:

http://localhost:8124/tags/

i get 404 error on the console because its trying to access the www folder with

/tags/www/ ....

im not sure how to solve this problem, thanks