Question : Compile more than one cs files in a dll (visual studio 2010)

I am trying to compile a dll from a project that contains many classes in VS 2010 (1 project many cs files). When I trying to use the resulted dll in an application I can see only the class from the first cs file and none of the rest. For example lets say I have two classes in two cs files A.cs and B.cs (A is the one created automatically when I start the project), and in the dll I can find only class A and not the B. I guess that I should enable something before compiling the dll but I couldn't find it. Thank you very much for your help in advance

Answer : Compile more than one cs files in a dll (visual studio 2010)

Have you made class b public?