Problem with updating salesdata view by using BAPI_MATERIAL_SAVEDATA

Hi Experts,

I am updating the material by using the bapi BAPI_MATERIAL_SAVEDATA.

I am exporting the data for the following views

CALL FUNCTION 'BAPI_MATERIAL_SAVEDATA'

EXPORTING

headdata = wa_headdata

clientdata = wa_bapi_mara

clientdatax = wa_bapi_marax

plantdata = wa_bapi_marc

plantdatax = wa_bapi_marcx

salesdata = wa_bapi_mvke

salesdatax = wa_bapi_mvkex

IMPORTING

return = wa_ret.

Bu the BAPI returna an error message as follows

"Enter a validity date"

There are any manditory fields are there in Clientdata or Salesdata structurers?

KIndly suggest me how to resolve this error.

Thanks

Brahma