void
  add_entry(hash)
          HV * hash
      PREINIT:
          SV * key;
          SV * val;
      CODE:
          key = sv_newmortal();
          sv_setiv( dt, (IV)someint );
          val = newSViv( (IV)otherint );
          hv_store_ent( hash, key, val, 0 );