noow i know generally how add a window, measure, cut out, insert moulding, insert window. but how would i work with this moulding. i saw an article but it said it should a have 3 grooves
http://www.pccasegear.com/index.php?main_page=product_info&cPath=1354_1355&products_id=19948
http://www.pccasegear.com/index.php?main_page=product_info&cPath=1354_1355&products_id=19948