When a user has completed filling out a form and no further changes are required they should 'Confirm' the form by clicking on the 'Confirm' button.
Before confirming the form will be validated to make sure that all fields with the 'Required to Confirm' flag set contain a value. The form cannot be confirmed until all required fields have been entered.
If the user just wants to save so they can make further changes at a later date then they should just save the form.
Once confirmed the form will be read only from this point. If no approval is required the form status will be moved staright to 'Completed'. If approval is required then the form status will go to 'Confirmed', a task will be created for the approver, and they will be required to approve the form to move it to a 'Completed' status.