  We give a direct computational proof of N=2 Seiberg duality for arbitrary
quivers, and find the action on the Fayet-Iliopoulos parameters. We also find a
new analogous classical duality for Kahler potentials of N=1 quivers that
generalizes the trivial duality Gr(N,N+M) ~ Gr(M,N+M) for Grassmannians.
