  In this paper, we first establish an evaluation formula to calculate Wiener
integrals of functionals on Wiener space. We then apply our evaluation formula
to carry out very easily calculating for the analytic Fourier-Feynman transform
of the functionals. Some examples are furnished to illustrate the usefulness of
the evaluation formula. Finally, using the evaluation formula, we establish the
series approximation for the analytic Fourier-Feynman transform.
