sql - how do i get opening and closing balance for each productCode -

how opening , closing balance each productcode using screenshot table. sql server 2008.
shot, product code 1 has been issued twice , last balance reflects current balance....i need last balance product codes.

  select top 1 balance openingbalance    stocktransfer productcode = 1 , transfertype = 'product'    , transactiondate between '2013-03-17' , '2013-03-22'     select top 1 balance closingbalance    stocktransfer productcode = 1 , transfertype = 'product'    , transactiondate between '2013-03-17' , '2013-03-22'    order transactiondate desc  

but works 1 product.

try this

select   (select top 1 balance openingbalance     stocktransfer     productcode = st.productcode , transfertype = 'product'     , transactiondate between '2013-03-17' , '2013-03-22'    ) opening balance,    (select top 1 balance closingbalance     stocktransfer     productcode = st.productcode , transfertype = 'product'     , transactiondate between '2013-03-17' , '2013-03-22'     order transactiondate desc    ) colosing balance    stocktransfer  st   transactiondate between '2013-03-17' , '2013-03-22'   group productcode  

this returns same result entire products