Example 2: Private function definition
This example shows how to define a private function.
This function will not be visible to other modules because it is declared as
PRIVATE for the module:
PRIVATE FUNCTION checkLength( name VARCHAR(50) )
  DEFINE ok BOOLEAN
  IF length(name) == 0 THEN
     LET ok = FALSE
  ELSE
     LET ok = TRUE
  END IF
  RETURN ok
END FUNCTION