Make a control required

Microsoft Office InfoPath

, you must make the control's field required. Depending on how you want to display error alerts and the flexibility of your form template, you can make the field required by displaying either a standard error message or a custom error message.

Note  If your form template prevents you from selecting the Cannot be blank check box in a control's Properties dialog box, you will need to display a custom error message.

ShowDisplay a standard error message when a control is left blank

ShowDisplay a custom error message when a control is left blank