A real-valued function u defined on an open subset $Omega of R^n (n geq 2)$ is said to be harmonic in $Omega$ if u is twice continuously differentiable and $Delta u = 0 in Omega, where Delta = sum_{i=1}^{n} frac{partial x_i^2}{partial^2}$. Let U be denote the open unit ball in $R^n$ and E(x) denote the fundamental solution of $Delta$, say, $$ E(x) = {C_1 log 1/$mid$x$mid$ if n = 2; {C_2$mid$x$mid$^{2-n} if n > 2. $$</TEX>