[MBA]

Surely, someone has wanted this feature? I guess my issue is there are a couple of governing tpls for the checkout cart especially the credit card information section (thanks for that tutorial balinor that was a treat). Adding a text box anywhere in there would be ideal, but I'd like to make it a required text box that checks for a phone number without .'s, -'s or spaces with a minimum number of numbers required and returns an error when letters are put in. The coding sounds easy enough, but which tpl would I tackle?
I can post back here with the how's and what's, I just need a little direction. Cheers!