Please check your user name and password error message when I am trying to log in andFBChat1.3.0 I installed andFBChat app on android emulator and when I am traying to log in using my facebook account , it says wrong username and password although they are right 

why !!
If you're sure they're right, the app is buggy and we can't help you, Facebook has changed their protocol/accessibility (and the app is out of date/won't work anymore) and we can't help you, or possibly you aren't connected to the internet and you should connect, or the port the app uses is blocked and we can't help you.