Making a Sample Win32 DLL project Using Visual Studio 2010 Professional

I made a Win32 DLL project  I called 'Win32DLLExample'. It compiles fine, and the DLL was created in its the Debug folder.
I also made a win32 executable project in Visual Studio 2010 to run and access the functions in the DLL:
I find it strange, but it looks like I can only have one project open at a time. When I open the new project the
other one closes.

Is that correct, in Visual Studio 2010?

Then, when I try to compile, it doesn't work of course:

------ Build started: Project: MyWin32CppApp, Configuration: Debug Win32 ------
Build started 1/30/2016 10:23:47 AM.
InitializeBuildStatus:
  Touching "Debug\MyWin32CppApp.unsuccessfulbuild".
ClCompile:
  Main.cpp
c:\documents and settings\user\my documents\visual studio 2010\projects\mywin32cppapp\mywin32cppapp\main.cpp(6): error C2871: 'Win32CppDLLExample' : a namespace with this name does not exist
c:\documents and settings\user\my documents\visual studio 2010\projects\mywin32cppapp\mywin32cppapp\main.cpp(12): error C2065: 'MyWin32ClassOne' : undeclared identifier
c:\documents and settings\user\my documents\visual studio 2010\projects\mywin32cppapp\mywin32cppapp\main.cpp(12): error C2146: syntax error : missing ';' before identifier 'sc1'
c:\documents and settings\user\my documents\visual studio 2010\projects\mywin32cppapp\mywin32cppapp\main.cpp(12): error C2065: 'sc1' : undeclared identifier
c:\documents and settings\user\my documents\visual studio 2010\projects\mywin32cppapp\mywin32cppapp\main.cpp(13): error C2065: 'sc1' : undeclared identifier
c:\documents and settings\user\my documents\visual studio 2010\projects\mywin32cppapp\mywin32cppapp\main.cpp(13): error C2228: left of '.Getvar' must have class/struct/union
          type is ''unknown-type''
c:\documents and settings\user\my documents\visual studio 2010\projects\mywin32cppapp\mywin32cppapp\main.cpp(14): error C2065: 'sc1' : undeclared identifier
c:\documents and settings\user\my documents\visual studio 2010\projects\mywin32cppapp\mywin32cppapp\main.cpp(14): error C2228: left of '.Setvar' must have class/struct/union
          type is ''unknown-type''
c:\documents and settings\user\my documents\visual studio 2010\projects\mywin32cppapp\mywin32cppapp\main.cpp(15): error C2065: 'sc1' : undeclared identifier
c:\documents and settings\user\my documents\visual studio 2010\projects\mywin32cppapp\mywin32cppapp\main.cpp(15): error C2228: left of '.Getvar' must have class/struct/union
          type is ''unknown-type''
c:\documents and settings\user\my documents\visual studio 2010\projects\mywin32cppapp\mywin32cppapp\main.cpp(17): error C2065: 'MyWin32ClassTwo' : undeclared identifier
c:\documents and settings\user\my documents\visual studio 2010\projects\mywin32cppapp\mywin32cppapp\main.cpp(17): error C2146: syntax error : missing ';' before identifier 'sc2'
c:\documents and settings\user\my documents\visual studio 2010\projects\mywin32cppapp\mywin32cppapp\main.cpp(17): error C2065: 'sc2' : undeclared identifier
c:\documents and settings\user\my documents\visual studio 2010\projects\mywin32cppapp\mywin32cppapp\main.cpp(18): error C2065: 'sc2' : undeclared identifier
c:\documents and settings\user\my documents\visual studio 2010\projects\mywin32cppapp\mywin32cppapp\main.cpp(18): error C2228: left of '.Getvar' must have class/struct/union
          type is ''unknown-type''
c:\documents and settings\user\my documents\visual studio 2010\projects\mywin32cppapp\mywin32cppapp\main.cpp(19): error C2065: 'sc2' : undeclared identifier
c:\documents and settings\user\my documents\visual studio 2010\projects\mywin32cppapp\mywin32cppapp\main.cpp(19): error C2228: left of '.Setvar' must have class/struct/union
          type is ''unknown-type''
c:\documents and settings\user\my documents\visual studio 2010\projects\mywin32cppapp\mywin32cppapp\main.cpp(20): error C2065: 'sc2' : undeclared identifier
c:\documents and settings\user\my documents\visual studio 2010\projects\mywin32cppapp\mywin32cppapp\main.cpp(20): error C2228: left of '.Getvar' must have class/struct/union
          type is ''unknown-type''

Build FAILED.

Time Elapsed 00:00:01.76
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========

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I already have additional include directories set up to cover the DLL header files:
BUT!
I cannot add reference to DLL project - no projects are selectable:

So, what can I do so that it compiles?

Also, once done, how can I run the compiles program and the compiled DLL together, outside the IDE?

Thanks.