BAPI_ACC_GL_POSTING_POST for g/l account & withholding tax details for fb75

Hello Experts,

Please please please help.

I have used the bapi BAPI_ACC_GL_POSTING_POST to post the g/l account details

document is generated successfully, now when i want to post the withholding tax details also through extension1 and userexit ZXACCU15(include), where coding done is as shown below

loop at t_accit. ( i have 3 line item inthis table)

t_accit-wt_key = '000001'.

modify t_accit.

endloop.

t_accwt-wt_key = '000001'.

t_accwt-witht = 'I1'.

t_accwt-WT_WITHCD = 'CC'.

t_accwt-WT_QSSHB = '200'.

append t_accwt.

in my document which is generated withholding tax details are not getting populated

please help

scenario is like this i am posting for amount 1000 inr and in my g/l account line item wise

i am posting 800- adn 200- and withholding tax should be calculated on 200 rs but nothing is working

also tried bapi bapi_acc_document_post but not successful

Regards,

tanvi