pal

Hey, I was going through some sites lately, and I realized some of them don't have an autofill function on login forms. I know that browsers support autofill and login info. remembering, but I was curious how you could do autofill and login information remembering with javascript, I'm thinking probably cookies? I heard from somone that you could do it with PHP?, but doing it with PHP didn't make sense since it's just a server side language, I would just stick with javascript and keep it simple, so if anyone has any idea how to do it with javascript I'll appreciate it.