is there any possibility while generating invoices customer is selected and a line item in invoice is entered, we can check previous records of sale rates to specific customer with invoice # only by pressing some button for the purpose. and same item can be checked against supplier invoice # with supplier rates by pressing a button on sale invoice line item while generating sales invoice?
This cannot be done. Depending on the edition (desktop, server, or cloud) and your operating system, there are ways of opening a second window with a different tab so you can, for example, look at inventory records while you are creating a sales invoice.
It will be difficult in a heavy database transactions to find sale rates for a specific customer and a specific item each time specially an item is entered, its much time taking process to probe it all for.
Note it as a suggestion for future if not possible now.
I don’t know either it is possible on manager or not because i am not a programmer. But i have seen it in other commercial accounting programs. I can send you snaps if u want proof.