FM 'SD_SALESDOCUMENT_CREATE'

hi experts,

i'm facing problem in creation of Credit Memo Request thru FM 'SD_SALESDOCUMENT_CREATE'-

i've passed the value of sold-to party(kunnr) in tables-

SALES_PARTNERS

PARTNERS_EX

but the FM still return the error for sold-to party and sales order can't be changed.

can ne1 please help me to change the sales order.

regards

Manish