I have tried alot to switch my Facebook  chat as Online but it never has. The problem is not with my Gmail contacts.
I can switch my Gmail Chat to online or offline the many times i want but I am unable to do so with my facebook  chat.
The same problem I am facing in my Windows 8 phone (Nokia Lumia 520) and in the phone both the Facebook  as well  as Google contacts appear offline to me.
Kindly give me a working suggestion because I have already tried most of the suggestion related to this problem.