Working with multiple forms

Question

I have 3 forms One is master form two other form inherit it and have same contents with some additional functions.
I want through master form Second form should open and through second form third form should open at the same time second form should get closed.

    I have thought to have some global object but it give runtime exception "An unhandled exception of type 'System.StackOverflowException' occurred in sysgeo.exe"
          If any body have idea please suggest.