Sometimes we click the box to save password for future button not to put the password for many times.But this also causes many difficulties and this is risky.If you are using some email in the lab and check market the box of "remember my password " and forgot to reset it before you are living the lab then anyone can enter into your account and can change your password.
Now what to do if such thing happen and what is the prevention.One solution is that use master password.Now the problem is what you will do if you forget the password or if someone already put the password?
In this case you can go to this link chrome://pippki/content/resetpassword.xul
By going to the above link you will see the below screen:
Now you need to press the "reset" button and then you will be able to reset the password which is mozilla master password.Hope you have liked the above technique.