Privious year sales in T-SQL

Hi all,

i have a trandate and tranvalue,customer,product now i need to poulate a table withtrandate,tranvalue(sales amount),customer,product,py_tranvalue  and i need to populate cy_WTD,cy_MTD,CY_YTD and py_WTD,PY_MTD,PY_YTD in sql server 2008 r2 usnig t-sql.

Can any one pls help.

Thanks & Regards,

Mahesh Babu k