How to put a password to "lock" the entire firefox?

[Green_Lantern]

Is there anyway to block any use of Firefox without a password? I sometimes have to share the computer and my sister started using firefox... and she would start new windows "erasing" the old ones, making me need to track it down the sites that I was using again, plus there is the... privacy issues.

 

[Andromache]

i think windows and mac both have guest user accounts. create one for her, and pswd lock yours. Easy.