Let $z_1,...,z_n$ be an n-tuple of distinct points in the open unit disk D in the complex plane. The classical Nevannlina-Pick interpolation problem is to find a function f(z) satisfying given interpolation conditions $$ (1.1) f(z_i) = omega_i, i = 1,...,n $$ and the stability constraint $$ (1.2) $mid$f(z)$mid$ leq 1, for z in D. $$</TEX>