Please Suggest Me Its Urgen Reg Ban

I have existing visa at qatar. The type of visa is work visa isuued last Nov 27, 2007 and to be expired on Nov 27, 2009 given by employer A . After issuance of visa by employeer A, I receive a good offer at employer B from Dubai.
I am going to India for vacation, and I want to join the Dubai Employer B
Question?
1.Is this visa can be cancelled automaticaly or expired with in the period of one (1) month due to the non appearance and action taken by both party (the company and employee) after it has been issued?
2.Do I need to get NOC or NOL from Employer A?
3.If the work visa was expired or cancelled due to non appearance and action taken by both party, Do I have a ban?
4 In future can I come to Qatar, Isn't right after 2Years ban to my arrival?
Kindly advice me what to do?
I had an employee that worked with me for 2 years without getting an NOC from his sponsor. We couldn't even find the guy or company. We paid off his penalties of QR12,000 and handed him over to authorities with his ticket back home. Once he left the country, I issued him a VISA through my company and he will be back in a week.
So, it plain LUCK :D
So good luck ..
make-up your mind. employer a or b? if you go for b your ban for two years in qatar unless employer a will give you noc if you want to go back here which i doubt empoyer a will give you. good luck. Pray thats the best!