sumproduct formula

[ermeko]

Hi,
I hava a workbook with 2 worksheets.

Sheet1 consists of 3 columns:
column A: invoice number
column B: "H" or "B" letters
column C: numerical value

Sheet2 consists of 10 columns:
column A: invoice number
column B: product item ID
column C: product weight
column D: price
column E: number of Items
column F: "H" or "B"

The task is:
1.For C column in Sheet1 to sum all the column E in Sheet2 having the same
Invoıce number as in Sheet1 column A and having the same letter in column F
as in sheet1 column B.

Thanks for help

Ermek