  We investigate the possibilities for constraining tan beta within the MSSM by
combining the theoretical result for the upper bound on the lightest
Higgs-boson mass as a function of tan beta with the informations from the
direct experimental search for this particle. We discuss the commonly used
``benchmark'' scenario, in which the parameter values m_top = 175 GeV and
M_susy = 1 TeV are chosen, and analyze in detail the effects of varying the
other SUSY parameters. We furthermore study the impact of the new diagrammatic
two-loop result for mh, which leads to an increase of the upper bound on mh by
several GeV, on present and future constraints on tan beta. We suggest a slight
generalization of the ``benchmark'' scenario, such that the scenario contains
the maximal possible values for mh(tan beta) within the MSSM for fixed m_top
and M_susy. The implications of allowing values for m_top, M_susy beyond the
``benchmark'' scenario are also discussed.
