I don't know how much you've done or coded of the general login area but I wouldn't use dermechove example above as it enters the data directly into the DB without checking for malicious script leaving you prone to exploits.

Personally I don't bother creating a login script every time from scratch every time I'm starting a new project as it's unnecessary and time consuming. I start with a base and modify it to my needs. For a great and easy to modify base I'd suggest http://php-login-script.com/ It has an admin area, validation, protection, simple admin area etc etc. all you need and will save you time. For a simple script and site like this it's ideal.

Then use litewarez idea of a separate table for the caller part and you'll be sorted. I wouldn't have it in the same table as the user details.