My form has various buttons. One button (button A) generates an Excel spreadsheet, saves it and e-mails it to a list of recipients. this whole process can take up to a minute. Other buttons perform various actions, which can involve changing or closing the tables button A uses. I had assumed that once button A has been pressed, the other buttons would remain unpressable until button A has finished. This is however not (always) the case. If my users accidentally press another button before button A is finished, an error can occur. In practice, telling the users not to press a button when the cursor is an hourglass is not sufficient. How can I effectively disable all the other buttons when one button is running?