how can I prevent 'hidden form fields' from 'view source' and 'file>save'

I am new to JavaScripting. I want to prevent some data like hidden form fields from getting saved on visitors computer when he uses 'File>Save' option or he tries to 'view source'. How to do this?

You can't. Simple as that. Anything you put on the web publically can be seen. Don't waste your time.

Best thing I can tell you is don't use hidden inputs. Generate the data you need on the server side rather than clientside.