Error while posting F-53

Hi All,

I have question in Accounts payable regarding (F-53)

My question is:

I have 3 purchase invoice from same vendor (F-43)

I  made 1st purchase @ 45000

I  made 2nd purchase @ 50000

I  made 3rd purchase @ 100000

total purchase 195000

I have paid 160000 for the above purchase

I want to clear full payments for 1st & 2nd purchase, then remaining for partial payment

I am use manual payment, but i am getting following error while posting (f-53)

Cash discount may only be granted up to 0.000 %

Could you please me on this....

thanks & regards,

K Kali Praveen