It might be good if some of our favourite sites login automatically when we open it.
You can login to a website automatically by keeping its cookie permanently in your browser. But this is safe only for a protected user account and not for a shared computer.
Open Firefox and then go to Tools > Options.
Go to the privacy tab and then, under the cookies click the exceptions button.
Then enter the URL of the sites for which you want to store the cookies permanently.
From now whenever you go to that site you will be logged in automatically unless you delete the cookies in your browser( by using the clear private data).