IF(VTK_USE_TK)
  VTK_GET_TCL_TK_VERSION ("TCL_TK_MAJOR_VERSION" "TCL_TK_MINOR_VERSION")
  SET (TCL_TK_VERSION "${TCL_TK_MAJOR_VERSION}.${TCL_TK_MINOR_VERSION}")
  IF("${VTK_TK_RESOURCES_DIR}" MATCHES 
     "${CMAKE_CURRENT_SOURCE_DIR}/tk${TCL_TK_VERSION}")
     SUBDIRS(tk${TCL_TK_VERSION})
  ENDIF("${VTK_TK_RESOURCES_DIR}" MATCHES 
        "${CMAKE_CURRENT_SOURCE_DIR}/tk${TCL_TK_VERSION}")
ENDIF(VTK_USE_TK)