formula for show monthly purchase stock, sale stock & balance stock

R/Sir
i am add new sheet name Monthly Report in this excel file than in monthly report sheet than i am choose September month than show Total Purchase
Stock, show total sale stock & show balance stock of September month total purchase stock data pickup from the the purchase sheet & total sale stock was pickup form the sheet2(1-9-2015), sheet3(1-10-2015),sheet4(2-10-2015), sheet6(3-10-2015) & than added new sheet(4-10-2015) sale stock this was included to monthly report total sale stock please send the formula for monthly report sheet Total purchase stock coulumn, total sale stock & balance stock columns, thanking you sir i am send the attachments sir please see the attachments sir