Need to be able to save LC form(s) if browser closes

I have many forms created in LiveCycle and put on our company website. I've gotten a few complaints from employees that when they type their forms and they accidentally close the browser instead of minimizing it they've lost everything they just finished typing. Is it possible to put a JS code in our forms so that if that happens they will get a prompt asking them if they want to save the form before they close the browser?

Thank you