Try to add DOEVENTS Command to the loop to allow VFP to process Windows messages.

>I have a [Start] and [Stop] commmand button on a form, when I press
>the [Start] button, it run a DO...WHILE loop until I press the [Stop]
>button. But I find that it not allow me to press the [Stop] button
>while the DO...WHILE loop are running.
>
>How can I press the command button while running in DO...WHILE loop ?
>