CakePHP URL Not Found

I am using Cakephp1.3 on ubuntu 11.10

i create table name users. I have a cake bake app. and user_controller, views and models are all present.

Now when I try to use http: // localhost / yps / users / , it gives the following error

Not found

The requested URL / yps / users / was not found on this server

Does anyone have an idea about this

thank