What is JotForm?
JotForm is a free online form builder which helps you create online forms without writing a single line of code. No sign-up required.
At JotForm, we want to make sure that you’re getting the online form builder help that you need. Our friendly customer support team is available 24/7.
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.
Depending on how you are pre-filling out the data fields.
If you want to prepopulate a field based from a field that is inside of the form itself, then using the "Update/Calculate Field" in the Conditions feature can do that.
Here's a guide that you can refer to: http://www.jotform.com/help/286-How-to-Populate-Field-with-a-Value-from-another-Field
If you are prepopulating directly from the form URL parameter, then that is possible by following this guide: http://www.jotform.com/help/71-Prepopulating-fields-to-your-JotForm-via-URL-parameters
If you wish to pass data from one form to another, then that is also possible, with the knowledge we learned from prepopulating via URL parameter, here's a specific approach for that: http://www.jotform.com/help/351-How-to-automatically-pass-form-data-to-another-form
Do let us know if you need more information on this.