Identificar El Numero Mayor En Visual Basic

Public Class Form1

    Private Sub button1_Click(sender As Object, e As EventArgs) Handles button1.Click
        Dim num1 As Integer, num2 As Integer, num3 As Integer, num4 As Integer
        num1 = Val(textBox1.Text)
        num2 = Val(textBox2.Text)
        num3 = Val(textBox3.Text)
        num4 = Val(TextBox4.Text)

        If num1 > num2 Then
            If num1 > num3 Then
                num4 = num1
                TextBox4.Text = num1
            Else
                num4 = num3
                TextBox4.Text = num3
            End If
        ElseIf num3 > num2 Then
            num4 = num3
            TextBox4.Text = num3
        Else
            num4 = num2
            TextBox4.Text = num2
        End If
    End Sub

    Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
        textBox1.Text = " "
        textBox2.Text = " "
        textBox3.Text = " "
        TextBox4.Text = " "
    End Sub

    Private Sub Button3_Click(sender As Object, e As EventArgs) Handles Button3.Click
        End
    End Sub
End Class