Go to next wizard step from Mass Action

I am using model API.But i am facing isuue.
Example:

First i have enter data for first name like Rooit and i am going on second step by clicking on next button.After that i think that I have done some spelling mistake so i am clicking on previous step and change the name to Rohit instead of Rooit but when i am getting first name value in java script it is Rooit. It is not changed in model.

So My question is how i can get changed value from wizard in java script.