How to login

Hi,

I have a typical scenario. Let me explain with an example.

Say I have 2 users A and B. A and B are portal users created in PCD.

So, I want to login with user A and on successful login ( need to login with user B ) and A should not know this background process.

Means once I login as A user, internally should login as B user.

Is there any way I can do this?

Thanks for your time.

Best Regards,

Shiva.