Apply Pament to invoices in form

[mmahmod]

Dear Gents

i have build a file to track the payment with the invoices for the sales rep
so i made the relationship is many to many
because i have three condition:
1- one payment to one invoice
2-one payment to multiply invoices
3-partaile payment to one invoice
all my problem in the form that mange this process
i want the user select first the sales rep then record a receipt by the payment then select from the query the invoices that not paid or still remaining
then i want after the selection finished ,update the table of transactions and i don't know how but i think its need a code to append and update the table by the selection