  We present a preliminary measurement of time-dependent CP-violating
asymmetries in B0 -> J/psi K0S and B0 -> psi(2S) K0S decays recorded by the
BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC. The data
sample consists of 9.0 fb-1 collected at the Y(4S) resonance and 0.8 fb-1
off-resonance. One of the neutral B mesons, produced in pairs at the Y(4S), is
fully reconstructed. The flavor of the other neutral B meson is tagged at the
time of its decay, mainly with the charge of identified leptons and kaons. A
neural network tagging algorithm is used to recover events without a clear
lepton or kaon tag. The time difference between the decays is determined by
measuring the distance between the decay vertices. Wrong-tag probabilities and
the time resolution function are measured with samples of fully-reconstructed
semileptonic and hadronic neutral B final states. The value of the asymmetry
amplitude, sin2beta, is determined from a maximum likelihood fit to the time
distribution of 120 tagged B0 -> J/psi K0S and B0 -> psi(2S) K0S candidates to
be sin2beta = 0.12+/-0.37 (stat) +/- 0.09 (syst) (preliminary).
