on init

  { These are preprocessor statements, which are not executed at runtime.
    They are instead processed at early parser stage. You can set a
    preprocessor condition with:
    
    SET_CONDITION(<condition-name>)

    Then you can use such preprocessor conditions to conditionally let the
    script parser know which code parts shall be used and which code parts
    shall be ignored. The ignored code parts will never be executed and thus
    will not waste any resources at runtime.

    There are also built-in coditions, already defined by the sampler, which
    allows you to execude script parts depending on certain circumstances.
  }

  SET_CONDITION(foo)

  { This will raise a warning, because it has already been set before. }
  SET_CONDITION(foo)

  USE_CODE_IF(foo)
    message("SET_CONDITION works.")
  END_USE_CODE

  USE_CODE_IF_NOT(foo)
    message("SET_CONDITION does not work!")
  END_USE_CODE

  RESET_CONDITION(foo)

  USE_CODE_IF_NOT(foo)
    message("RESET_CONDITION works.")
  END_USE_CODE

  USE_CODE_IF(foo)
    message("RESET_CONDITION does not work!")
  END_USE_CODE


  SET_CONDITION(bar)

  USE_CODE_IF(bar)
    SET_CONDITION(bla)
    USE_CODE_IF(bla)
      message("Nested conditions work.")
    END_USE_CODE
    USE_CODE_IF_NOT(bla)
      message("Nested conditions do not work!")
    END_USE_CODE
  END_USE_CODE

  { If you uncomment the following, it will throw an error. }
  { RESET_CONDITION(somethingthatdoesnotexist) }

end on