I have a worksheet on which I need a sum of data for accounts using info from
another worksheet if the data on the second worksheet is associated with a
given account on the first worksheet.

Example:

On worksheet 1:

Acct Description Total
5001 Account 1 ???
5002 Account 2 ???
5003 Account 3 ???
5004 Account 4 ???
etc

I want to fill in the "Total" column for each account using info from
Worksheet 2:

Invoice Acct Total
1001 5001 100
5002 200
1002 5001 50
1003 5003 500
5002 300
1004 5004 300
5001 300

So for acct 5001, the total is 450
5002 - 500
5003 - 500
5004 - 300

I need to look on worksheet 2, match the account number from worksheet 1 and
sum the info from worksheet 2 in the total column on workheet 1.

Thanks in advance for help.

Marc