> How do I implement a Cancel button that will stop certain processing
> to stop upon the clicking by the user?

>> How do I implement a Cancel button that will stop certain processing
>> to stop upon the clicking by the user?
>Use a TSpeedButton. Read about properties Down, AllowAllUp, and
>GroupIndex.

>In article <30D98AD8.4...@hia.no> Bent Tranberg <Bent.Tranb...@hia.no> writes:

>>Chi Tsi wrote:

>>> How do I implement a Cancel button that will stop certain processing
>>> to stop upon the clicking by the user?

>>Use a TSpeedButton. Read about properties Down, AllowAllUp, and
>>GroupIndex.

>Bogus response...  :-{

>You need to do the following things:

>{1}  Define a boolean flag somewhere called "cancelled."  Set it to false
>before you begin processing, and periodically test to see if it has become
>true.  If it has, bail out.

>{2}  The "onClick" routine of some button -- pick a button -- must set this
>flag to true.

>{3}  Your code must yield to Windows at regular intervals.  Here is a routine
>that I use to do this:

>       procedure doEvents;   {sorry.. first name that came to mind ;-}
>       begin
>          if application.Terminated then abort;
>          application.ProcessMessages;
>          if application.Terminated then abort;
>       end;