>>>>I will try it. You mean INKEY() without a parameter so that no to slow down the loop even more, right?
>>>>
>>>>Thank you.
>>>
>>>Actually, I meant that you can allow user input, e.g. I usually run following message during similar loop:
>>>wait "Processing... Press Ctrl-S To Abort.' window nowait
>>
>>Another alternative may be to test mouse coordinates and mousedown at some critical points of the loop and see if the button was pressed this way.
>
>I was thinking along those same lines. I will try this approach later.

If you set some "global" variable in the button's click (pInterrupt = .t.) would it work?