title: express checkout keep loading and didn't return to merchant
body: <p>I am using paypal sandbox to doing testing, however after click the continue button that i wish to complete the transaction, but the page is keep loading. So i click to go back on the browser, and then click to go forward again, then it will only display "You've already completed your purchase. Please click Close to continue to the merchant." My problem is i want it auto return me the success page, but not click the back and forward to view the return to merchant. thanks you very much and appreciate your answer.</p>