2 worksheets, need to merge and/or match

I have a worksheet (invoices) that is missing data that I have on another worksheet (acctlist). How do I match the acct # on the invoices worksheet with the account names from worksheet acctlist. Thanks for the help! Attached is a small sample.

In B2, and copy down:

=VLOOKUP(A2,acctlist!$A$1:$B$18,2,FALSE)

You saved me again! Thanks so much!