How can I stop autofill on facebook main page when I log-in?

[Mia]

Ok, so here's a little problem. My son's friends used my lab-top to get into their Facebook account, and since then, every time I try to log from the Facebook mainpage, a few different email addresses automatically shows on that log in box. I went into internet option and unchecked auto filling (not sure exactly but there were a couple of different options and I unchecked them all) but when I am on the Facebook main page, and try to log in, the email addresses automatically still popped up.

So how can I stop this autofill on the Facebook main page? Please anyone, help! I would really appreciate your response. Thank you.