RB Parts description

Can anyone help me how to create a calculate field on DESCRIPTION OF PARTS
ARE SOLD?

I got a report called customer name sales and database joins.

vantage.customer to vantage.InvcHead
vantage.InvcHead to vatnage.InvcDtl

Marites Marlar
MCP, MCSE, MCSE + I, A+, CNA
MIS Department
SPS Non-Ferrous
(702) 262-9922 ext. 118