A form’s control box property usually controls both the system menu(control box) and the close button (X in the top right corner) on the form.If the ControlBox Property is set to True, your form will have both a controlbox and a close button. You can make a dialog from a form without the controlbox, but with a close button by setting ControlBox to True, Icon to Noneand Borderstyle to 3 (Fixed Dialog).