  The level splittings induced by a horizontal magnetic field in a parabolic
two-dimensional quantum dot with spin-orbit interaction are obtained.
Characteristic features induced by the spin-orbit coupling are the appearance
of zero-field gaps as well as energy splittings that depend on the electronic
state and the orientation of the magnetic field in the quantum-dot plane. It is
suggested that these quantum-dot properties could be used to determine the
Rashba and Dresselhaus spin-orbit intensities
