ดู CODE VB2008 โปรแกรมเช่่ารถยนต์ให้หน่อยค่ะปรับเปลี่ยนตรงไหน

Public Class Form1
    Private Sub ComboBox1_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ComboBox1.SelectedIndexChanged

        Select Case ComboBox2.SelectedIndex
            Case 0
                Label3.Text = "ชั่วโมง"
                Price.Text = 880
                TextBox1.Focus()
            Case 1
                Label3.Text = "วัน"
                Price.Text = 1200
                TextBox1.Focus()
            Case 2
                Label3.Text = "สัปดาห์"
                Price.Text = 1500
                TextBox1.Focus()
            Case 3
                Label3.Text = "เดือน"
                Price.Text = 2500
                TextBox1.Focus()
        End Select

    End Sub

    Private Sub DateTimePicker1_ValueChanged(ByVal sender As System.Object, ByVal e As System.EventArgs)

    End Sub

    Private Sub Price_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs)

    End Sub

    Private Sub ComboBox2_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ComboBox2.SelectedIndexChanged

        Select Case ComboBox2.SelectedIndex
            Case 0
                ComboBox2.Text = "ชั่วโมง"
                Price.Text = 880
                TextBox1.Focus()
            Case 1
                Label1.Text = "วัน"
                Price.Text = 1200
                TextBox1.Focus()
            Case 2
                Label1.Text = "สัปดาห์"
                Price.Text = 1500
                TextBox1.Focus()
            Case 3
                Label1.Text = "เดือน"
                Price.Text = 2000
                TextBox1.Focus()

        End Select

    End Sub

    Private Sub UserControl1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

    End Sub

    Private Sub TextBox2_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Price.TextChanged

    End Sub

    Private Sub Label3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Label3.Click

    End Sub

    Private Sub TextBox1_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TextBox1.TextChanged

    End Sub

    Private Sub TextBox3_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TextBox3.TextChanged





        TextBox2.Clear()
        TextBox2.Text += "   เช่ารถยนต์ทั้งหมด      " & TextBox1.Text & "           " & Label3.Text & vbCrLf
        TextBox2.Text += "   ราคาทั้งสิ้น                " & TextBox2.Text & "   บาท" & vbCrLf
        TextBox2.Text += "   รับเงินทั้งสิ้น              " & TextBox3.Text & "   บาท" & vbCrLf
        TextBox2.Text += "   เงินทอน                   " & (TextBox3.Text - TextBox2.Text).ToString() & "   บาท" & vbCrLfผิด


    End Sub
End Class