How to Avoid Seen Notification IN Facebook Chat

Hie Frnd's Today We Are Going 2 See How To "Avoid Seen Notification" IN Chat Box . 

Some Time's We Want 2 See The Msg Of Our Frnd's IN Facebook , But Don't Want 2 

Notify Him/Her That We Saw The Sent Msg BY Him/Her . :D :D

So It IS Possible .. Yes !

IT Can be Possible BY Using Some Addon or Extension's .

For Mozilla FireFox :

For Google Chrome :

So Now You Can Freely Read All UnSeen Msg's IN FacebooK , Without Notifying Your Frnd  :D