  We use the supergravity modes to clarify the role of the prefactor in the
light-cone superstring field theory on PP-wave background. We verify some of
the proposals of the recent paper hep-th/0205089 and give further evidence for
the correspondence between N=4 SYM gauge theory and string theory on PP-wave.
We also consider energy-preserving processes and find that they give vanishing
cubic interaction Hamiltonian matrix.
