Dynamic calculations in RadDataGrid

Question

I have 2 radDatagrid in the name of itemGrid and GridView.  Respective columns in itemGrid "Sno", "Item", "Rate", "Qty", "Amount", "Delete" & GridView columns are "Sno","Customer Name","Item","Rate","Qty","Amount". Rate * Qty displayed on Amount Column. My question s whenever i add or deduct values the transaction made need to be reflect on the itemGrid. How can that be. Can any1 help. I need it ASAP ...