couple of Question on sunnah of the Prophet P.B.U.H

[Infoseeker]

my first question is ,


1) is it compolsery to wear a hat for man when praying salaat ?


2) When traveling away from your city you can pray travel pray , but if you see a Jammat in a mosque and you join and just pray the main pray , can you then combine it with another pray example


you walk into the mosque and join Zhur pray after which you just pray two rakat Asr pray.


3) and finally I was reading on the Jinn book and came across Zar cicirule can someone in a nut shell explain to me what it is and which Islamic contry use to practise this act.


your support is helpful.