Arabic as a foreigner language, what to teach dialect or MSN or both ?

Language Resource Center - Arabic

Living Arabic ISBN 13: 09780974484341
Dr Munther Younes the outher of the above text book wrote in his text book page IX ( I DAY believe that teaching a spoken dialect for everyday conversation and MSN for reading, writing, and formal speaking is the most effective way to prepare students to function in Arabic. I also believe that if a student masters any Arabic dialect well enough, he /she will be able to function in other dialects, just as native speakers from different area of the Arab world do.)

I met Dr Munther Younes in Madrid Arabela 09 where he explained how he teach his methods: dialects and MSN side by side.
Arabs from different parts of the Arab world speak different dialect, but MSN is virtually the same everywhere.However students who learn to speak only MSN they may use it in conversation,and they may hear the answer with local dialect hence they will find it difficult to understand what is being said to them.
I beginning to agree with Dr Munther Younes, above all Dr Al Batal in his new issues of (al-kittab) introduced THREE new dialect in addition to the Egyptian. In my visit to Texas University this year I saw how the students speak MSN mixed with Egyptian dialect* I was very impressed.
*By the way Dr al-batal is not Egyptian contrary to some believe.

But the question is in what stage should we teach the dialect?

Also reed about Amia (In my Blog end of September):
http://www.shorouknews.com/ContentData.aspx?id=122882

In this link you well hear and see the Levantine Arabic.
http://lrc.cornell.edu/medialib/ar

http://lrc.cornell.edu/medialib/ar/aei1
http://lrc.cornell.edu/medialib/ar/aei2