Public Class Form1
    Private Sub txtUsername_TextChanged(sender As Object, e As EventArgs) Handles txtUsername.TextChanged
        If txtUsername.Text.Length < 8 Then
            lblUsername.ForeColor = Color.Red
            lblUsername.Text = "X"
        Else
            lblUsername.ForeColor = Color.Green
            lblUsername.Text = "O"
        End If

    End Sub

    Private Sub txtPassword_TextChanged(sender As Object, e As EventArgs) Handles txtPassword.TextChanged
        Dim rawPassword As String
        Dim upper, lower, eight, special, number As Boolean
        upper = False : lower = False : eight = False : special = False : number = False
        Dim ascValue As Integer

        rawPassword = txtPassword.Text

        For counter = 0 To rawPassword.Length - 1
            ascvalue = Asc(rawPassword(counter))
            Select Case ascValue
                Case 65 To 90
                    upper = True
                Case 97 To 122
                    lower = True
                Case 48 To 57
                    number = True
                Case 32 To 47, 58 To 64, 91 To 96, 123 To 126
                    special = True
            End Select
        Next

        If rawPassword.Length >= 8 Then
            eight = True
        End If

        If upper = True And lower = True And eight = True And special = True And number = True And special = True Then
            lblPassword.ForeColor = Color.Green
            lblPassword.Text = "O"
        Else
            lblPassword.ForeColor = Color.Red
            lblPassword.Text = "X"
        End If
    End Sub

    Private Sub txtReenter_TextChanged(sender As Object, e As EventArgs) Handles txtReenter.TextChanged
        If txtReenter.Text = txtPassword.Text Then
            lblReenter.ForeColor = Color.Green
            lblReenter.Text = "O"
        Else
            lblReenter.ForeColor = Color.Red
            lblReenter.Text = "X"
        End If
    End Sub

    Private Sub txtPhoneNo_TextChanged(sender As Object, e As EventArgs) Handles txtPhoneNo.TextChanged
        Dim formatString As String

        If txtPhoneNo.Text.Length <> 10 Or Not (IsNumeric(txtPhoneNo.Text)) Then
            lblPhoneNo.Text = "X"
            lblPhoneNo.ForeColor = Color.Red
        Else
            lblPhoneNo.Text = "O"
            lblPhoneNo.ForeColor = Color.Green
        End If

        formatString = txtPhoneNo.Text.Substring(0, 3) & "-" &
            txtPhoneNo.Text.Substring(3, 3) & "-" & txtPhoneNo.Text.Substring(6, 4)
        txtPhoneNo.Text = formatString

        lblPhoneNo.Text = "O"
        lblPhoneNo.ForeColor = Color.Green
    End Sub
End Class