Phone number validation in Advanced forms

I am a little surprised that Advanced forms doesn't offer PHONE as a field option. Has anyone figured out the best way to do this in Advanced forms without being too hacky?

View Replies:
jasteele12 replied on at Permalink Reply
Do a Google search for "validating phone numbers"

This is *not* an easy problem to solve, as there are *many* rules that also change over time.

If you happen to want to just validate US numbers, it's a bit easier - follow some of the links from the search above...
GrizzlyAdams replied on at Permalink Reply
I guess I didn't really mean "Validate". The core form block had a telephone field type. Was surprised that Advanced Forms doesn't.