fiesta airbag light seat change

[chopper54]

hi all
i have a 96 mk4 ford fiesta and i changed the seats for mk5 ford fiesta zetec s seats i replaced the mk4 female side of the seat connectors with the mk5 zetec ones but my airbag light is flashing in groups of 4 , i have read since that i should have changed the pretensiors on the seats but this is not a option as i dont have the original seats any more , what do i need to do to stop the air bag light from flashing,

thanks