  The pseudorapidity dependence of elliptic flow in Au+Au collisions at 130 $A$
GeV is studied within a full three-dimensional hydrodynamic model in the
light-cone coordinate. First, we prepare two initial conditions in the
hydrodynamic model for analyzing elliptic flow. Both initial conditions lead to
reasonable agreement with single particle spectra in central and semi-central
collisions. Next, by using these hydrodynamic simulations, we compare elliptic
flow as a function of pseudorapidity with experimental data recently measured
by the PHOBOS Collaboration. Our results are in agreement with experimental
data only near midrapidity. This suggests that thermalization in the early
stage of collisions is not achieved in forward and backward rapidity regions.
