help with Windows Application project

Hi all,

I have a windows application project in visual studio 2005. I want to test a class using windows application. How do i reference my class. I am writing

using Files; (namespace of my class) but i get an error saying the type or namespace Files couldn't be found. I have various buttons to test the class on windows form. Just want to know how can i reference the class. Do i need to add the namespace to the add reference in solution explorer because when i do that it works. But, i think by just writing using Files (namespace of my class) i should be able to access the class in my windows application project.

Thanks