How to Hide Yourself From Selected Friends In Facebook Chat

How to Hide Yourself From Selected Friends In Facebook Chat: "Say you have just began chatting with your girlfriend on Facebook and suddenly some random stranger starts sending instant messages. In case of strangers and people whom you don’t know, you can always ignore the instant message and continue chatting with the person you were chatting with. But the situation gets worse when some close friend starts sating “Hello, how you doing” and you are busy fixing a date with your girlfriend."