Working in Find Mode 
Use the Find mode to display data you have already entered in SAP Business One. The following example finds an existing A/R invoice.
Choose .
The A/R Invoice window opens in the Add mode.
Switch to Find mode in one of the following ways:
Choose in the menu bar.
Press Ctrl + F.
Choose
(Find) in the toolbar.
Enter the search criteria, for example, the customer code, and choose Find.
A single invoice or a list of invoices appears.