Auto Increment file name in Sharepoint Form infopath

Question

I used this as my reference:

Auto-numbering InfoPath forms when they are submitted to a SharePoint form library

I followed that link but it wont work correctly,instead of having 1,2,3... as filename it creates NaN as it's file name.. what should I do?

look at the image:

Answer 1

NaN is the error code for "not a number". The steps you take to increment do not result in a number. If you are using the MAX() function as described in the tutorial, check that the field you are using in that function is a number, not text.

Note the "caveat" on the tutorial: If the library does not yet contain any documents, the Max() function will return NaN. You must name the first form manually.