How can I pre populate a form based on a value entered by the user?

Hi, I had used Jotform last year to create an online registration for a series of children's classes. Now I need to conduct the same exercise again. But now I already have the registration details of the children. Each child has been allotted a regitstration number. Is it possible for me to create a form where if they enter their registration number, the system can pull the related data such as child's name / age / gender / classes opted for etc. from an existing database (already in Jot form) so that they dont have to enter these details again?

I am not being able to figure this out. Would really appreciate help. Thanks, Sandy 

Hi hscw,  

Thanks for contacting us.

Unfortunately, you will need custom and complex programming with this. Currently, the only way to pre-populate a form is via URL Parameters. 

Do let us know if you need further assistance. 

Regards.