I am having trouble turning a selection from a drop down box into a defined
value.

I am currently using a drop down box with 21 different options for people to
select. I would like to have these different options create a running total
on a different part of the sheet. As an example I will use produce (since
this seems popular):

A1 B2 C2 D2
D3 D4

Purchase Date Customers One Apple Orange Grapes
Etc.
" " Customer Two " " " "
" " " "
" " Customer Three

The way I would like this sum to work is if Customer One purchases an Apple,
Orange, and Grape it will total it on another part of the sheet with the
corresponding name like so:

Apple: 1
Oranges : 1
Grapes : 1

But also I need the functionability whereas Customer Two purchases only an
Apple and Orange it keeps the totals running respectively, i.e.:

Apple : 2
Oranges: 2
Grapes : 1

My goal for this is to know exactly how many Apples, Oranges, Grapes were
sold on a weekly basis to keep a running tally. Furthermore, lets say
Customer Three Purchases two Apples and nothing else but I want to make sure
that they only use one row under each customer so buying habits can be
tracked, i.e.:

A1 B2 C2 D2
D3 D4

Purchase Date Customers Three Apple Apple


Apple : 4
Oranges: 2
Grapes : 1

I understand that I could just put a column next to each possible drop down
box where the employee can place a "1" and just work from there but there is
21 different possibilities to calculate and it could make things more
difficult for the employee. I apologize for all the reading and any help
would be much appreciated!