treatment of cash discount ,freight,scheme discount in purchase bill

Pls ellaborate your question, not able to understand your query....

If i undertsood correctly, your problem is, how to account cash discount received in purchase bill which is negative balance .

Very simple account the purchase net of discount 

example

Item    Rate     discount       Price

Item 1 100           10              90

Item 2  100           5               95

JV

Item 1(InventoryA/c)  A/c  Dr   90

Item 2 (Inventory A/c) A.c Dr   95

         To Vendor A/c/ Bank               A/c   185

I hope this answer your query