Thank you very much for your reply.
These are my detail.
I created my Infopath form template and publish to SharePoint Document Library in specific site. At first of operation, user create new form (from my created template) and then user submit at first time for file creation into document library, this new file name is generated from xxxx + now() function. (That I set "Main submit" in data connection).
After that, user re-open this file for edit. And then user submit form again for saving data (I don't want to use save function), I want to use "Second submit" data connection that I want to use the same file name (Gereated at first time) for this submission.
Please suggest me for solving solution by using function fx at Data Connection Creation.
Or if you have other solution, you can suggest me for additional information.
Thank you very much again.