No particular form is necessary to constitute a will. To determine whether an instrument is a will, the test is the intention of the maker to be gathered from the whole instrument, read in light of the surrounding circumstances. If the intention is to convey a present interest, though the possession is postponed until after death, the instrument is not a will. If the intention is to convey an interest accruing and having effect only at death, the instrument is a will.
OCGA § 53-4-3