I have an excel spreadsheet:
family
first name
last name
product

in my excel spread sheet i can have the same family name more than once, with different product.:

row 1
Mr. and Mrs. Smith
Sam
Smith
ABC

row2
Mr. and Mrs. Smith
Sam
Smith
GHI

row 3
Mr. and Mrs. Smith
Sam
Smith
xyz

in my mail merge letter i want:

Dear (family_name)

(body of the letter)

list of (product) abc
ghi
xyz

sincerely,
Acme Group

I started the mail merge using Mailing -> Start Mail Merge -> Directory Select Receipiants -> chose my spread sheet and made sure its sorted by Family_Name

inserted all my merge fields

how do i check when the family_name changes in the excel spread sheet and i have a new letter for the next family??