pre filling a form with the data of the previous form?

I have a submission form where parents can subscribe their child in a school.
See here: http://tinyurl.com/cn9v8km
When the first child is subscribed, the form must ask it they want to enter a 2nd child.
If yes, the new form (with a different layout) must be prepopulated with the data from the first child (address, phone, email etc).
Is there a way to achieve this?

If you're looking to copy the input from one field to another on the SAME form and page then look here.
http://www.gravityhelp.com/forums/topic/how-to-populate-a-hidden-field-with-een-other-field#post-81974

Adding the code below to your functions.php will get the job done.

<?php

add_action("gform_pre_submission", "pre_submission_handler");
function pre_submission_handler($form){
    $_POST["input_14"] = "new value for field 14";
}
?>