Thank you Qatarisun and sandeep for your reply.

Qatarisun I understand.

I am leaving for qatar on 21st OCT 2009...so my visa will be valid for 30 days i.e., till 20th Nov 2009.
I will extend the visa for another 60 days (30+30) i.e., till 20th Jan 2010.
Do I need an exit every time I extend the visa or only when leaving after completing 90 days????
(I mean, do I need an exit to extend the visa every 30 days??)

Also, lets say I have completed 90 days in qatar and need more time...my sponsor is ready to issue me another business visa. In this case can I visit neighboring country like Behrain for couple of days and return qatar on new business visa??? (instead coming back to india)
Thank you guys.
Muzaffer.