Missing FFTW_LIBRARIES

Hi, sorry to open an issue here.

I tried to compile xkin. I already have cmake, FFTW and freenect. (I used windows 7). However, I'm stuck with Missing FFTW_LIBRARIES message. I already add FFTW location to the PATH system variable.
I guess cmake doesn't recognize FFTW path. How could I fix this? I don't see any path parameter in find_package method.

Thank you in advance.
