#include "isajet/pilot.h"
      COMPLEX*16 FUNCTION SSB0(QSQ,M1,M2)
#if defined(CERNLIB_IMPNONE)
      IMPLICIT NONE
#endif
      COMPLEX*16 SSF0
      DOUBLE PRECISION XLAM
      REAL QSQ,M1,M2
      COMMON /SSINF/ XLAM
      SSB0=XLAM*(1.D0,0.D0)-SSF0(QSQ,M1,M2)
      RETURN
      END