[Help-gsl] Trouble installing gsl/gsl_math.h using XCode

[C W]

Hi list,
I have downloaded gsl-1.0 from the website.  I am using it inside XCode.  I
have trouble setting the path correctly.

The error message I get is:
'gsl/gsl_math.h' not found.

So, I actually went to copy that file and pasted into the same folder as my
c code.  But it gives me other files not found.

How am I suppose to correctly set this up?

Thanks,
Mike