#6 Auto save password without any notification in firefox.

1) First of all you need to close firefox.

...tl;dr 2) Now locate the nsloginmanagerprompter.js file which is normally found in
C:\ProgramFiles\MozillaFirefox\Components\

3) Open nsloginmanagerprompter.js with notepad or other editor. But the editor which would show the line number will be ideal.

4) Replace the entire line 804 to 869 with the following code
var pwmgr = this._pwmgr;
pwmgr.addLogin(aLogin);

After replacing this, save this file
Now it's done...