Function to standardize a telephone number.

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Public Class Form1

    Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
        Dim RawPhoneNumber As String = "(800) 555-1212"
        Dim StandardizedPhoneNumber As String = StandardizePhoneNumber(RawPhoneNumber)
        MsgBox("Phone number: " & RawPhoneNumber & ControlChars.CrLf & "Standardized: " & StandardizedPhoneNumber)
    End Sub

    Public Function StandardizePhoneNumber(ByVal PhoneNumber As String) As String
        If PhoneNumber Like "*###*###*####*" = True Then
            PhoneNumber = System.Text.RegularExpressions.Regex.Replace(PhoneNumber, "\D", "")
            If PhoneNumber.StartsWith("1") = False Then
                PhoneNumber = "1" & PhoneNumber
            End If
            If PhoneNumber Like "###########*" Then
                Dim PhoneNumberValue As ULong = Val(Strings.Left(PhoneNumber, 11))
                PhoneNumber = PhoneNumberValue.ToString("0-000-000-0000")
            End If
        End If
        Return PhoneNumber
    End Function

End Class