How can I update the value of a product option before ajax

I have a product with a custom form page. I would like to take the data collected from the form(name, birthdate, etc.) and update the values of text options for that product. The data is being stored in session variables currently but at the end of the process i would like to put them in an option array attached to a product in the cart.

If you have all data, why not change the options value n text with jquery?