Firefox: Remember new passwords without prompting

How can I make Firefox automatically remember all passwords without prompting?

Answer

Hacking Firefox to Always Auto Save Password Without Showing Notification Bar:

1. Close Firefox


2. Edit nsLoginManagerPrompter.js with notepad which is normally located in C:\Program Files\Mozilla Firefox\components\


3. 
   

   Replace the entire lines 642 to 711 with the code below:

   
   

   var pwmgr = this._pwmgr;
   pwmgr.addLogin(aLogin);
   

Now whenever you login to any website, Firefox will auto save the site, username and password to the login manager WITHOUT showing the notification bar.

Note: even when you enter the wrong username or password, it will still be saved.

Source