InfoPath Dev

I have a form that is used in the capicity for owners of Role-based profiles to submit profile modification requests and new role-based user requests.  There is a submit button that sends the form as an email with attachment to our Technical Support Center (this will generate a ticket), and it also writes it to a Sharepoint Document library for technicians (and the users completing the form) to view.  I don't want changes to be made to the form (even by the requestor) once submitted.  Is there a way to make the form ReadOnly for all viewers once the form has been submitted?

 You can make a separate view that is a "read-only" view and have a "Submitted" field in your form that is set to true immediately before submitting.  Then have a form-open rule that switches the form to the read-only view if that field is true.