Validating Data
One advantage of using Submit rather than Save is that Submit enforces data validation. InfoPath allows you to save forms containing invalid data, but you can't submit the form until all fields are valid. InfoPath can validate fields using a variety of criteria. To add validation criteria to a control:
Display the control's properties and click Data Validation. InfoPath displays the Data Validation dialog box.
Click Add. InfoPath displays the dialog box for validation criteria. Enter a condition that results in a validation error.
Click OK and then preview the form and test the validation.
You can combine multiple criteria by choosing And >>, but you can only have one ScreenTip and Message per control.
Validation rules are checked as the user enters data on the form. If an invalid entry is made in a control, that entry is flagged as soon as the focus moves to another control.
Forms containing validation errors can't be submitted, but users only receive a warning if they save or email a form containing validation errors. There is no built-in way to prevent the user from saving, emailing, or printing a form containing validation errors, but you can avoid it by following these steps:
Choose Tools → Form Options → Open and Save. Disable the Save, Print, and Send to Mail Recipient options. Click OK to close the dialog box.
Add buttons to the form to save, print, or submit the form.
Add a checkbox to enable or disable the save/print/esp2_submit buttons as described in "Customizing ...