TOPIC: PayPal Pro Payment - Click once button?

Hi Nathan and DTH Team,
We have a small issue. We use PayPal Payments Pro on DTRegister. When the user enters their credit card info, and hit's submit, there is some lag between the time they hit submit and a response coming back from PayPal. So, I assume users are hitting submit multiple times. Could you possibly include a click once JS or something to keep users from hitting submit multiple times? We only get one reg if they do, but we get multiple payments, and have to go into PayPal and refund them. Please advise what you can do. Thank you in advance for your help! -Scott