C# if/then directives for debug vs release

In Solution properties, I have Configuration set to "release" for my one and only project.

At the beginning of the main routine, I have this code, and it is showing "Mode=Debug". I also have these two lines at the very top:

#define DEBUG 
#define RELEASE

Am I testing the right variable?

#if (DEBUG)
            Console.WriteLine("Mode=Debug"); 
#elif (RELEASE)
            Console.WriteLine("Mode=Release"); 
#endif

My goal is to set different defaults for variables based on debug vs release mode.