=If(B15="","",VLOOKUP(B15,Products,2))

But if B15 does not appear in the products table, you will get an error
(which in this case may be desirable).

"Excel Student" wrote:

In an invoice I am making I want to use the vlookup function to populate a
description column and a unit price column when I type in a product item
number. I have a product table set up with the item number, description and
unit price on it. However, when I do not have an entry in the product item
numberin the invoice, an error message appears in the description column and
unit price column which does not make a good appearance for my invoice.

How to I put the =If(B15="","","") function in the vlookup function
=VLOOKUP(B15,Products,2)