[Cmake] CMAKE_BACKWARDS_COMPATABILITY irix 6.5.18m

[Dengfeng Liu]

                                                                                         Hi, 
 I got these Error when I have INCLUDE(${CMAKE_ROOT}/Modules/FindFLTK.cmake) in CMakeLists.txt

CMake Error: Error: An atttempt was made to access a variable: CMAKE_X_LIBS that has not been defined. Some variables were always defined by CMake in
 versions prior to 1.6. To fix this you might need to set the cache value of CMAKE_BACKWARDS_COMPATIBILITY to 1.4 or less. If you are writing a CMakeList
 file, (or have already set CMAKE_BACKWARDS_COMPATABILITY to 1.4 or less) then you probably need to include a CMake module to test for the feature this
 variable defines.

While no error message when I did not include this line although I have this line:
INCLUDE(${CMAKE_ROOT}/Modules/FindITK.cmake)

How can I get rid of this warning while still using the new version of ccmake?
Thanks

Dengfeng