  We present an application of the reduction of couplings program in the
minimal supersymmetric Standard Model (MSSM). We investigate if a functional
relation between $\alpha_1$ and $\alpha_2$ gauge couplings can be realized
which is Renormalization Group Invariant (RGI). Following the same procedure
for the top and bottom Yukawa couplings we end up with a prediction of a narrow
window for tan$\beta$, which is one of the basic parameters that determine the
light Higgs mass.
