VB.NET ดูโค้ดหน้า Login ให้หน่อยครับ รันไม่ผ่านเวลาใส่รหัสหรือ ไอดีผิดครับ

Private Sub OK_Click(.....
If txtuser_ID.Text = "" And txtpassword.Text = "" Then
MessageBox.Show("ใส่ข้อมูล", "No userID", MessageBoxButtons.OK, MessageBoxIcon.Error)
Else
If ReadMyData(txtuser_id.text,txtpassword.text) = false then
Messagebox.Show("Username And Password ไม่ถูกต้อง")
end if
end if 

end sub


Private function ReadMyData (ByVal userid As String,ByVal password As String) as boolean
if Cnn.State = ConnectionState.Open then Cnn.Close()
Cnn.connectionstring = Cnnstring
Cnn.Open()

sqlselect = "select * from mytable Where id = '" & userid  & "' and Password = '" & password   & "'"
Dim da  as New SqlDataadapter(sqlselect,Cnn)
dim ds as New Dataset

da.fill(ds,"dtLogin")

if ds.rows.count = 0 then
return false
end if 

return true
end function

if sqlreader.HasRows Then

Else

End IF

 Imports System.Data
Imports System.Data.SqlServerCe





Public Class Login
    Dim Cnn As New SqlCeConnection(Cnnstring)
    Dim Cnnstring As String
    Dim sqlselect As String
    Dim sqlreader As SqlCeDataReader
    Dim userida As String
    Dim passida As String
    Dim myConnection As SqlCeConnection = New SqlCeConnection("Data source=D:\Project New\WindowsApplication1\WindowsApplication1\Database1.sdf;")
    Dim myCommand As SqlCeCommand
    Dim myConn As SqlCeCommand
    Dim cmdString As String


    Private Sub OK_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles OK.Click

        
        With Cnn
            If .State = ConnectionState.Open Then Close()
            .ConnectionString = Cnnstring
            myConnection.Open()
            myConnection.Close()
        End With
        If txtuser_ID.Text = "" And txtpassword.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
            myConnection.Open()

        End With
        sqlselect = "select * from mytable Where id = '" & txtuser_ID.Text & "' and Password = '" & txtpassword.Text & "'"



        Dim sqlcommand As New SqlCeCommand(sqlselect, myConnection)

        sqlreader = sqlcommand.ExecuteReader
        sqlreader.Read()
       if sqlreader.HasRows Then

        userida = CStr(sqlreader.Item("id"))
        passida = CStr(sqlreader.Item("password"))
end if

        If txtuser_ID.Text = userida And txtpassword.Text = passida Then
            chair.Show()
            txtuser_ID.Text = ""
            txtpassword.Text = ""
            Me.Hide()
        Else


            MessageBox.Show("กรุณาใส่ข้อมูลให้ถูกต้อง", Me.Text, MessageBoxButtons.OK, MessageBoxIcon.Warning)

        End If
    End Sub

 Imports System.Data
Imports System.Data.SqlServerCe





Public Class Login
    Dim Cnn As New SqlCeConnection(Cnnstring)
    Dim Cnnstring As String
    Dim sqlselect As String
    Dim sqlreader As SqlCeDataReader
    Dim userida As String
    Dim passida As String
    Dim myConnection As SqlCeConnection = New SqlCeConnection("Data source=D:\Project New\WindowsApplication1\WindowsApplication1\Database1.sdf;")
    Dim myCommand As SqlCeCommand
    Dim myConn As SqlCeCommand
    Dim cmdString As String


    Private Sub OK_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles OK.Click

        
        With Cnn
            If .State = ConnectionState.Open Then Close()
            .ConnectionString = Cnnstring
            myConnection.Open()
            myConnection.Close()
        End With
        If txtuser_ID.Text = "" And txtpassword.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
            myConnection.Open()

        End With
        sqlselect = "select * from mytable Where id = '" & txtuser_ID.Text & "' and Password = '" & txtpassword.Text & "'"



        Dim sqlcommand As New SqlCeCommand(sqlselect, myConnection)

        sqlreader = sqlcommand.ExecuteReader
        sqlreader.Read()

       If sqlreader.HasRows Then

                userida = CStr(sqlreader.Item("id"))
                passida = CStr(sqlreader.Item("password"))
       End If
        If txtuser_ID.Text = userida And txtpassword.Text = passida Then
            chair.Show()
            txtuser_ID.Text = ""
            txtpassword.Text = ""
            Me.Hide()
        Else


            MessageBox.Show("กรุณาใส่ข้อมูลให้ถูกต้อง", Me.Text, MessageBoxButtons.OK, MessageBoxIcon.Warning)

        End If
    End Sub

    Sub myDataReader()
        Dim strSQL As String
        Dim dtReader As SqlDataReader
        strSQL = "SELECT * FROM customer "
        dtReader = clsDB.QueryDataReader(strSQL)

        '*** Bind Rows ***'
        If dtReader.HasRows = True Then
            Me.lblCustomerID.Text = dtReader.Item("CustomerID")
            Me.lblName.Text = dtReader.Item("Name")
            Me.lblEmail.Text = dtReader.Item("Email")
            Me.lblCountryCode.Text = dtReader.Item("CountryCode")
            Me.lblBudget.Text = dtReader.Item("Budget")
            Me.lblUsed.Text = dtReader.Item("Used")
        End If
        clsDB.Close()
    End Sub