How do I auto generate a number for each form filled out?

[dianah]

I need to auto generate an ID for each form filled out, for example RTC-1,
RTC-2, RTC-3. This needs to be automatic every time a user opens a form to
fill out and then saves it. Does this need a formula or is this a script?

 

[Russ]

The problem is that there is no way for the form template itself to keep
track of how many times it has been filled out. The only way I can think of
to do this is to link the form to a database (or something similar) that will
generate a unique ID for each form that queries the database.

 

[Dana]

You need to develop a web service which will return a unique number for every
document. You have to put a button on the InfoPath form which will connect
to the web service to get the unique number and after that will save the form.
The unique number is stored in a SQL database or xml file (I recommend sql
database if you are in a multi-user environment)