Visual Basic

Private Sub SSN_Validating(ByVal sender As Object, ByVal e As System.ComponentModel.CancelEventArgs) Handles SSN.Validating
    Dim tempSSN As String = String.Empty
 
    ' Create a temporary string that contains only the
    ' numbers in the original string as typed by the user.
    For i As Integer = 0 To SSN.Text.Length - 1
        If IsNumeric(SSN.Text.Chars(i)) Then
            temp &= SSN.Text.Chars(i)
        End If
    Next
 
    If tempSSN.Length = 9 Then
        ' We should have a string of numbers that looks like this: 295048397
        ' Reformat it to look like this: 295-04-8397
        SSN.Text = String.Format("{0}-{1}-{2}", _
            tempSSN.SubString(0, 3), _
            tempSSN.SubString(3, 2), _
            tempSSN.SubString(5, 4))
        SSN.BackColor = Color.White
        e.Cancel = False
    ElseIf tempSSN.Length <> 0 Then
        ' If the length is now anything other than 0 or 9, clear
        ' the textbox and color it red to point out that we need a valid
        ' SSN in this box to continue.
        SSN.Text = String.Empty
        SSN.BackColor = Color.Red
        e.Cancel = True
    Else
        ' Since the SSN length is 0, it's OK to not have an SSN.  Clear
        ' the textbox and return it to normal.
        SSN.Text = String.Empty
        SSN.BackColor = Color.White
        e.Cancel = False
    End If
End Sub

Private Sub Button1_Validating(ByVal sender As Object, ByVal e As System.ComponentModel.CancelEventArgs) Handles Button1.Validating<br />
<br />
 If Phone.Text.Length = 12 Then<br />
            MsgBox("You have entered a valid phone number")<br />
        ElseIf Phone.Text.Length <> 0 Then<br />
            Phone.Text = String.Empty<br />
            Phone.BackColor = Color.Red<br />
            e.Cancel = True<br />
        Else<br />
            Phone.Text = String.Empty<br />
            Phone.BackColor = Color.Plum<br />
            e.Cancel = False<br />
        End If<br />
    End Sub