Sorry, there is no such option. The Password Manager has the optional Master Password that requires the MP be given before the Password Manager fills in any fields.

Why do you require a lock on Firefox? We can give you workarounds.

i would like it so that i can block certain people from seeing Fire Fox on my computer. as this is the only internet option on this pc at this time it is important to me so i can block them from seeing what i am doing when i am done with the computer. i have sensitive work that i do on here

You can put a password on your computer user profile.

This, I think, is what you really want;

Mozilla Firefox, Portable Edition {web link} A fully functional package of Firefox optimized for use on a USB key drive. A specialized launcher will allow most favorite extensions to work as you switch computers.

ok thank you for your help. i do have a password on the user profile but i would like to have an extra precaution all the same. thank you again

Hello,

I am glad to hear that your problem has been resolved. If you haven't already, please select the answer that solves the problem. This will help other users with similar problems find the solution more easily.

Thank you for contacting Mozilla Support.