Charlie,
Thanks for your advice. I am really trying to get a command button to stop a long series of routines from finishing, similar to the 'Phone dialer' in Windows. I know that the 'Escape' key will stop code from running. I have created a form with two command buttons ('RUN' and 'STOP') and a timer. I have set the timer Interval to 1/1000 of a second and a Wait Window with a Timeout of 5 seconds in the timer event. While the Timer is firing I can not click on the 'STOP' button to interrupt the Wait Window (the Wait Window simulates code running). Any advice?