>>>>You cannot guarantee that a timer won't switch the alias on you.
>>>
>>>Well written timer action code can handle this. But really asynch behavior like keyboard interrupts or asynch return from old style OLE-Linking and embedding can still throw wrenches in such code ;-)
>>
>>There is stuff that is unable to survive badly written asynched events.
>>A
>>

>>REPLACE;
>> Alias.Field WITH VALUE;
>> FOR condition;
>> IN Alias
>>

>>Will die silently, if async code sets the current workarea to something different then alias, but on EOF, as far as I remember.
>>
>>

>>SELECT alias
>>SCAN
>>

>>is helpless, if workarea is changed in between.
>> ¯\_(ツ)_/¯
>
>The last sentence is wrong, Scan will take care of changing the work area back to the correct one.

ENDSCAN will. Altered between SELECT xxx and SCAN, SCAN knows nothing about the area selected.