' Validate a US phone number
' Example:
' MessageBox.Show(IsValidUsPhoneNumber("(123) 456-7890")) ' True
' MessageBox.Show(IsValidUsPhoneNumber("(123) 456-78901")) ' False
Function IsValidUsPhoneNumber(ByVal phnNum As String) As Boolean
Return System.Text.RegularExpressions.Regex.IsMatch(phnNum, _
"^((\(\d{3}\) ?)|(\d{3}-))?\d{3}-\d{4}$")
End Function