  We study the frequency-dependent magnetoconductivity of a strongly correlated
nondegenerate 2D electron system in a quantizing magnetic field. We first
restore the single-electron conductivity from calculated 14 spectral moments.
It has a maximum for omega ~ gamma (hbar gamma is the disorder-induced width of
the Landau level), and scales as a power of omega for omega ->0, with a
universal exponent. Even for strong coupling to scatterers, the
electron-electron interaction modifies the conductivity for low and high
frequencies, and gives rise to a nonzero static conductivity. We analyze the
full many-electron conductivity, and discuss the experiment.
