Here is some sample code

Do While Thisform.KeepLooping
oCurrentObject = Sys(1270)
If oCurrentObject.Name = "cmdCancel"
DoEvents
Endif

*/ Your code that gets executed...
EndDo

You only want to invoke DoEvents when your mouse is over the cancel button. This will help preserve performance. The exit button can set the keeplooping property to .F..

HTH...