Hi Tom,
A simple regular expression would be:
^[0-9]{3}-[0-9]{3}-[0-9]{4}$
Or if you want to get more specific, since the first digit of the NPA (area code) and NXX (exchange) can not be 0 or 1 (assuming these are North American phone numbers)
^[2-9]{1}[0-9]{2}-[2-9]{1}[0-9]{2}-[0-9]{4}$
Explanation of the regular expression
^ => start at the beginning of the line
[2-9] => range 2 to 9
{1} => must be 1 digit long
[0-9] => range 0 to 9
{2} => must be 2 digits long
- => must be the "-" character
[2-9] => range 2 to 9
{1} => must be 1 digit long
[0-9] => range 0 to 9
{2} => must be 2 digits long
- => must be the "-" character
[0-9] => range 0 to 9
{4} => must be 4 digits long
$ => end of line
FYI: AwareIM also requires a / at the beginning and end of the input mask.
