Use this tab to enter invoice lines with delivery type, Tax code, amount, etc. At least one line has to be entered for an invoice. Normally, one invoice contains one line, but there can be more if, for example, the invoice has different Tax amounts or delivery types.
If the company for which you are entering the invoice is using the Net Amount Entry as the entry method, and you want to enter a gross amount for a particular invoice, or vice-versa, right-click on the window and then click Swap Net/Gross Amount Entry.