You cannot prevent someone from saving a document based on the value of one or more form fields, if that's what you want.
First, the 'submit' with regard to the 'requite' field property, is a submit to a web server scripting page, not a 'submit' button.
So do you want your users to only to be able to save the form if they complete the form?
Then lock them into a loop to the uncompleted field until they complete the field. Not a very user friendly approach.
There is a 'will save' action that can also check for the completion of required fields. You will need to decide what action you want taken, but you can not stop the save action.
Erase the data.
Mark the form as incomplete.
Have an alert window pop-up.
You can not also stop one from printing an incomplete form through the 'Will Print' action.
You may need to write a document level script to check all of the required fields and take some action as needed. This could be used by a number actions like will save, will print, email form, submit to a web server.
Thanks all for your reply.
I used the Document Will Save event to give users warning before they save the document and set focus back to the first un-filled required field
Combined with the "on-blur" event on each individual required field, I think it could eliminate most unfilled fields.