Cmake error while configuring OpenCL program

Ive made a new OpenCL project by writing proper CmakeLists files, but still Im getting the following error

"CMake Error at CMakeLists.txt:10 (find_package):
By not providing “FindOpenCL.cmake” in CMAKE_MODULE_PATH this project has
asked CMake to find a package configuration file provided by “OpenCL”, but
CMake did not find one.

Could not find a package configuration file provided by “OpenCL” with any
of the following names:

OpenCLConfig.cmake
opencl-config.cmake

Add the installation prefix of “OpenCL” to CMAKE_PREFIX_PATH or set
“OpenCL_DIR” to a directory containing one of the above files. If “OpenCL”
provides a separate development package or SDK, be sure it has been
installed."

please tell me the reason why do I get this error…!