JotForm is a free online form builder which helps you create online forms without writing a single line of code. No sign-up required.
We believe that if one user has a question, there could be more users who may have the same question. This is why many of our support forum threads are public and available to be searched and viewed. If you’d like help immediately, feel free to search for a similar question, or submit your question or concern.
I apologize if I have the difficulty understanding your question since is not in English.. but from what I gotten so far, I think you were looking for the Unique ID field to use in your form.
Check this user guide: -Add-Custom-Unique-IDs-to-your-Form-Submissions
Hope this help. Please let us know if you need further assistance.