How To add The GridView Footer Total To Paypal BuyNow Button

Question

hi

I Have a Custom Created shopping Cart GridView..In That Gridview Footer Total Amount Of Items is Displayed..

Now I Have A Button "Buy Online"..When I Click On The Button The GridView Footer Total Amount Should Be Integrate With The Paypal And Ask For Credit/Debit Card Details...Please Help Me...I Had Tried alot but not Find out...