I want that certain fields in my form must be numeric.
I'm using the "if_numeric" code for that.
But if I submit a form with a phone number that contanes a dash, It will not be accepted.
Example:
Phone: 1516-678-9010
Will not be accepted.
However, only such a number will be accepted:
Phone: 15166789010
So, how to I add a "DASH" to the "Whitelist"?