  Fortran subroutines to calculate helicity amplitudes with massive spin-2
particles (massive gravitons), which couple to the standard model particles via
the energy momentum tensor, are added to the {\tt HELAS} ({\tt HEL}icity {\tt
A}mplitude {\tt S}ubroutines) library. They are coded in such a way that
arbitrary scattering amplitudes with one graviton production and its decays can
be generated automatically by {\tt MadGraph} and {\tt MadEvent}, after slight
modifications. All the codes have been tested carefully by making use of the
invariance of the helicity amplitudes under the gauge and general coordinate
transformations.
