check out of joomla+virtuemart creating problem

[ruchita]

hello friends,

i am using joomla + virtuemart when i click confirm order it redirect me on sandbox paypal but give error "We cannot process this transaction because there is a problem with the PayPal email address supplied by the seller. Please contact the seller to resolve the problem. If this payment is for an eBay listing, you can contact the seller via the "Ask Seller a Question" link on the listing page. When you have the correct email address, payment can be made at www.paypal.com"

i am testimg for sandbox paypal plz suggest me how to over come this problem??