[CMake] Question about c99

[David]

Hello,

This might be a stupid question but I'm new to c and cmake so I don't know 
much about it yet.

I would like to be able to use the for construct like this: 
for(int i = 0; ..., 
if I understand correctly I need c99 for this. I think I also need it for the 
bool keyword. Is this correct?

Do you know how I can tell cmake to compile my program as c99?

Currently my CMakeLists.txt looks like this:

PROJECT(UFO C)
LINK_LIBRARIES(readline)
ADD_EXECUTABLE(ufo ufo.c)

Thanks,
David