ผมลองเขียน Class ติดต่อกับฐานข้อมูลแต่กลับ Error ครับ ไม่รู้เขียนยังไงจึงจะถูกครับ

Imports System.Data
Imports System.Data.OleDb
Public Class Database
    Public connection As New OleDbConnection
    Public connect As String
    Public cmd As New OleDbCommand
    Public adapter As New OleDbDataAdapter
    Public data As New DataSet
    Public sql As String

    Public Sub New()
        connect = "Provider=Microsoft.Ace.OleDb.12.0;" & "Data Source=score.accdb"
        connection = New OleDbConnection(connect)
        connection.Open()
    End Sub
End Class

Public Class Main
    '  Public con As Database
    Dim connection As New OleDbConnection
    Dim cmd As New OleDbCommand
    Dim adapter As New OleDbDataAdapter
    Dim data As New DataSet
    Dim sql As String

    'Sub connectdatabase() 'ฟังก์ชั่นย่อยใช้ในงานเชื่อมต่อฐานข้อมูล
    '    Dim connect As String = "Provider=Microsoft.Ace.OleDb.12.0;" & "Data Source=score.accdb"
    '    connection = New OleDbConnection(connect)
    '    connection.Open()
    'End Sub
    Sub loaddata()
        sql = "Select * from Student"
        cmd = New OleDbCommand(sql, connection)
        adapter = New OleDbDataAdapter(cmd)
        data = New DataSet()
        adapter.Fill(data, "Student")
    End Sub
    Private Sub Main_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Dim database As New Database
        ' connectdatabase()
        loaddata()
    End Sub

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Idstudent.Text = data.Tables("Student").Rows(0)("Idstudent")
        connection.Close()
    End Sub
End Class