What should be the test scenarios in unit test case for a typical login page in WPF

What should be the test scenarios in unit test case for a typical login page in WPF?

I am new to writing unit test cased and could not found much help in the internet. It would be great help if someone can guide me through this. I have to write for a complete module and I can take the idea from your suggestion to write unit test cases for all the pages in the module.

Any refrence would also be helpful for me.

Thanks :)