Difference between work at, work with and work for

If someone asks me where do I work, what should my reply be, I work at "this store", I work for "this store" or I work with "this store".

I am really confused about it.

[hani05]

work with

[sairashab]

thanks ! :) ... Can you please tell me when do we use the other forms? I mean when do we use work at and work for?

[Dextrous]

Actually I would say work at in this context. I'll give an example for each:

I work at McDonalds. (The name of the company)
I work with Brian. (The name of a co-worker)
I work for Mr Stevens. (The name of your boss/manager)

That is the general difference between these phrases.

[sairashab]

Thanks! that helped :)