Working in Add Mode 
Use the Add mode to enter new data, such as business partners, items, or sales and purchasing documents, in SAP Business One. The following example adds a new customer.
Procedure
Choose
Business Partners 
Business Partner Master Data 
.The Business Partner Master Data window opens in the Find mode.
Switch to the Add mode in one of the following ways:
In the menu bar, choose
Data Add .Press Ctrl + A.
In the toolbar, choose
(Add).
Specify the necessary data, and choose Add.
Result
You have created a new business partner record.