You can use a form property as a flag, you set it up to .t. when the process starts and reset it to .f. when the process ends, now you only allow the form to close when the flag is .f., for doing so you can check in the queryunload of the form as well as in the button that you use for exit, if you have one. The code for the query unload would be something like:

if thisform.ProcessIsRunning
   nodefault
endif

>I have a modeless form. When the user selects an 'Execute' button on the form how to prevent the user from then closing the modeless form while the method is executing? The 'Execute' commandbutton does not close the form at completion. But I do not want the user to try to close the form either in the middle of the process as it may be long running (I am displaying a status indicator). Thanks.

[Update]Doh, silly answer. sorry