I ve following Master detail tables

Sales (SaleID,CustomerID, SaleDate)
SaleDetails (SDetailID, ProductID,Quanity,Price,SaleID)
I have AccountingTrans tables as Follows

Journals (JID, JDate,SaleID)
JournalDetails (AccID,Dr,Cr)
My Account are linked with Customer and Product. Now i want to use trigger to automatically enter three transaction(in case of two Products in detail entry) in JournalDetails table. I am able to insert Product balances but don't know how to insert Customer (Sum of SKU amounts) entry in journalDeails table

I am using ASP.net mvc with EF to save the invoice