When a user presses the Cancel button, the control that previously had focus triggers its LostFocus event, which is where many programs do their validity checking. If the input wasn’t filled, as is often the case when the user clicks on Cancel, the validation may display a message. The user won’t expect this after clicking on Cancel, and shouldn’t ever see it.To avoid this problem, add a form-level variable to indicate if Cancel has been clicked on. In the Cancel’s MouseDown event, set it to True. In the MouseUp event, set it back to False-this way the LostFocus event occurs between the two.One more catch-if the user activates the Cancel button with a mouse-down click on the Cancel button, changes his or her mind, and moves the mouse off the Cancel button and then “mouse-ups,” you still have it set to Cancel. So set it to False in the MouseMove event of the parent of the Cancel button. To avoid doing validations, check against your Cancel Pressed variable.