Thank you so much also as i am the sponser will i be troubled or pay fine if am am  giving my visa for cancellation and  while i am leaving.

my vis a is expiring on june 2012 but my assignement wil complete on september 2011 my wife will go back on 3rd sept but i will go back on 29th sept, so i have to apply for my visa cancellation or i can just go simply with exit permit.please reply thanks!