Yes this is possible.
This for i would suggest you to create a DATABASE .
All data, which will be filled out on the form , will be directly saved inside a database, everytime some changes have been made.
The simplest way would be a DATASET, which would save DATA on each maden change on the form .
You CHANGE → dataset SAVES into DATABASE !
You leave the site? —> No problem!
You come back later and open your page again.
While page loads, it automaticaly also takes a look into your database and loads all data from database back into your form .
The same way, you use your dataset again for loading the data into your form .