The "!=" means that if the variable does not equal 0 do something, so it will ignore the 0. what you want is something like this using the OR operator, (not sure if i used the correct syntax for OR but in C++ it is ||:
What is he checking for though? He's not doing "if (x == whatever)" he's doing "if (x == anything)"...
A veriable ALWAYS has a value. The default is 0 [zero]. What he's trying to do isn't possible in 3DGS. You can use "ifndef - endif" to see if a DEFINE xxxx has been defined, but not with var's...