To get NOC this is what you have to do
You have to bow down in front of your employer and tell him Sir please please let me join the other company. Even when I have joined the other company I will keep on working for you free of charge. If he does not agree tell him Sir I will pick your kids from school. I will wash your (stinky) feet. I will even do your house chores. Still if he does not agree. Sir every year I will take you to Thailand and you will not have to go to Bahrain. I promise that you will get all type of pleasure there which you cannot get in Bahrain.
Still not working, then get a gun and shot the ***** in his balls

(NOTE: If this does not work we will return your money)