TT will not allow my credit card payment to efile? After entering my credit card security code the blue "continue" button is grayed in and will not allow me to push it.

We accept credit, debit, and pre-paid cards with a Visa, MasterCard, American Express, or Discover logo. Like many other U.S. online merchants, we can only process cards with a U.S. billing address. 

I'm putting in the correct CC # but it will not allow me to hit "continue" on that screen.  It is grayed in and when hit it does not go through,