Why does it say im offline when i log into facebook ?this is most frustrating ,please help?

for the past 2months or so, everytime i login to facebook it keeps saying i am offline an i ain on chat i go into the settings but i hve no sucsess ,this is most frustrating to me and my freinds ,mostly my family '' knwone knws if im online ,please could you ist me wiv this problem and hopfully sort it out ,many thanx