monitor is shaking little bit top left

hai,
this is uday. my monitor is shaking little bit on top left side. i dont know what make it turn like this. and i dont have stepliger or ups i connected directly to the socket and give the details actual cause which make this shaking and have i any solvable things to do to stop the shaking…..pls help me..kiran_7302000@yahoo.co.in