facebook wont show when friend messaged me?

[BOOMBAH]

if i have more than one tab and im not on my facebook tab, usually when someon emessages me it will say "_____ messaged you" but for one of my friends, it wont show it. plus, when i go to my inbox, her name isnt there, even though i have just recently messaged her. i have to search for her name to get to the messages. PLUUSSS, her name does not come up where it shows who is onine, even when she is online.

[Edson]

This link has several tutorials for Facebook: http://www.trafegoweb.com/2013/05/tutori...ebook.html