thanks a lot, helpufill. But..

I really want to know who's tax return? mine or employer? Right now I live in Canada,and I don't have 3 year tax return with w-2. please give me more advice.
thanks again.
Also, For affidavits of support, which required less than 12 months when present to the consular officer, is it an offical form like I864 or a letter from empoyer?