Cannot call SetFocus from within a When, Valid, RangeHigh or RangeLow event (Error 2012)

The SetFocus method conflicts with these events, which are testing to see if the object can get or lose focus.

• You are calling SetFocus from a When event.

  Call SetFocus from the GotFocus event instead.

• You are calling SetFocus from a Valid,RangeHigh, or RangeLow event.

  Call SetFocus from the LostFocus event instead.