[Cmake] IF statement in CMake

[Asad A. Abu-Tarif]

Hi,
I started using CMake to control the compilation of my
registration package (that uses vtk heavily).
In my package, I'm supporting several vtk versions.
In my CMakeLists files, I added a value for VTK_VERSION
using:
SET (VTK_VERSION 3.2 CACHE VALUE "VTK version" )

Now, I would like to use a statement like:
IF (VTK_VERSION < 3.2)
    do some things
ELSE ....etc.

It seems that IF doesn't accept the 'less than' expression.

Is something like this doable in CMake??

Sorry if this is a repeated question.
Regards,
Asad
       __________________________________________________
     /                        Asad A. Abu-Tarif
\
     |   Computer Engineering.
|
     |   PhD Candidate, Rensselaer Polytechnic Institute (RPI).       |
     |   tarifa at rpi . edu
|
     \___________________________________________________/