จะถามเรื่อง VB 2008 ติดต่อกับฐานข้อมูล Access2007 การเข้าสู่ระบบพอดีกำลังหัดทำคะ ขอบคุณคะ

Imports System.Data
Imports System.Data.OleDb
Public Class Form1
    Dim Cnn As New OleDbConnection(Cnnstring)
    Dim Cnnstring As String
    Dim SqlSelect As String
    Dim OleReader As OleDbDataReader
    Dim UserIDA As String
    Dim PassIDA As String

    Private Sub cmdlogin_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmdlogin.Click
        Cnnstring = "provider=Microsoft.ACE.OLEDB.12.0;Data Source=D:\ปวส\2\โปรเจ็ค\ระบบจัดการฐานข้อมูลรับ-ส่งหนังสือ\WindowsApplication1\WindowsApplication1\bin\database\login.accdb"
        With Cnn
            If .State = ConnectionState.Open Then Close()
            .ConnectionString = Cnnstring
            .Open()
            .Close()
        End With
        If usertxt.Text = "" Then
            MessageBox.Show("ใส่ข้อมูล", "No UserID", MessageBoxButtons.OK, MessageBoxIcon.Error)
        Else
            ReadMyData(Cnnstring)
        End If
    End Sub
    Public Sub ReadMyData(ByVal myConnString As String)
        On Error GoTo 0
        With Cnn
            If .State = ConnectionState.Open Then Close()
            .ConnectionString = Cnnstring
            .Open()
        End With
        SqlSelect = "select * from tbuserlogin Where Username = " & "'" & usertxt.Text & "'"
        Dim OleCommand As New OleDbCommand(SqlSelect, Cnn)
        OleReader = OleCommand.ExecuteReader
        OleReader.Read()
        UserIDA = OleReader.Item("username")
        PassIDA = OleReader.Item("password")
        Cnn.Close()
        If usertxt.Text = UserIDA And passtxt.Text = PassIDA Then
            Form1.Show()
            usertxt.Text = ""
            passtxt.Text = ""
            Me.Hide()
        Else
            MessageBox.Show("กรุณาใส่ข้อมูลให้ถูกต้อง", Me.Text, MessageBoxButtons.OK, MessageBoxIcon.Warning)
        End If

    End Sub
End Class