InfoPath Dev

Using SP & IP 2010, I created a form library that contains my InfoPath form. Then created a document library where the form is used for both create and edit.  I am passing a field (CustomerName) as my file name. That was so users could click on the customer name to launch the form for editing.  My problem is this:  If they edit an existing record - and modify the Customer Name, an additional record is created.  Is there a simple way to set a rule or condition that when Editing, my CustomerName field is Read Only?

(I did create a duplicate form with CustomerName read only, renamed to Edit and tried to get that form to load upon Edit but couldnt get it to work.)

Corrie Sigler 

You could have a temp field that you write a value on save/submit and perform a check on load whether this value is there. Then you would have a rule check this field and disable the control.

Alternatively, qRules has an isNew function which will check whether the form has not been saved or submitted.