Custom Fields - payments that have added a $ symbol

I setup a form for payments and the below URL. However, if a payment is entered in digits only ie: x.xx it properly auto sums in the "total Amount" field. But if the user places $ before the digits (as is common in the USA) it will not auto sum. As you can see i included wording that says "digits only" but I would prefer that the form just understand the $ symbol when there and properly auto sum. Is there a work around for this?

www.scba.org/new/pay-your-annual-dues.html

Thank you.

Hello Barry

I just updated some code in the extension to handle this case. Please access to My Downloads menu item, download latest package, upgrade it to your site, then check it again. It should work well

Tuan