查询数据代码出现问题

各位网友好，现有一窗体作为查询界面，根据资料书写代码如下
Public Class Form1
    Dim mybind As BindingManagerBase
    Dim strconn As String = "provider=microsoft.jet.oledb.4.0;data source=mingdan.mdb"
    Dim objconn As New oledbconnection(strconn)
    Dim objadap As New oledbdataadapter
    Dim objdset As New DataSet
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Dim strsql As String
        objconn.open()
        objdset.Clear()
        If Trim(TextBox1.Text) = "" Then
            strsql = "select * from huojiang"
        Else
            strsql = "select * from huojiang where 获奖等级='" & TextBox1.Text & "'"
        End If
        Dim objadap As New oledbdataadapter(strsql, objconn)
        objconn.close()
        objadap.fill(objdset, "huojiang")
        DataGridView1.DataSource = objdset.Tables("huojiang")
    End Sub   
End Class
运行时提示如下
错误    1    未定义类型“oledbconnection”
错误    2    未定义类型“oledbdataadapter”   
错误    3    未定义类型“oledbdataadapter”
请问错在哪里，应如何处理 。
请指导，谢谢
程序在附件中

[ 本帖最后由 燕之峰 于 2014-11-19 15:57 编辑 ]