using_cost_seaice=.TRUE.
using_cost_seaice=.FALSE.
& using_cost_sst, using_cost_seaice,
IF (using_cost_seaice) call COST_GENCOST_SEAICEV4( mythid )
& using_cost_seaice
logical using_cost_seaice
& using_cost_seaice=using_gencost(k)