How to exclude source file from a build in Visual Studio

Problem:

Applies to Visual Studio 2003 and 2005

COBOL .NET project contains serveral source files.  How to compile just one of those source files?

Resolution:

In Solution Explorer, for each source file that you do NOT want to compile, right click on it and select Properties.  In the Properties window set Build Action to 'none'.  By default it is set to 'Compile'.