I have repeatedly accidentally lost data as I entered it in a form. Here is what happens. I am filling out a form. I am about half way through. I realize I don’t know the value I should enter for a particular field. In my browser, I navigate out of the form to go find out this information. I come back to the form an the form is now empty. When I navigate away, I would like a warning “Do you want to save your data?”.