myConnection.Open()
    rtb_Address.Clear()
    txt_Name.Clear()
    Dim str As String
    str = "SELECT * FROM table1 WHERE (cus_ID = '" & txt_ID.Text & "')"
    Dim cmd As OleDbCommand = New OleDbCommand(str, myConnection)

    dr = cmd.ExecuteReader()

    While dr.Read()
        rtb_Address.Text = dr("cus_Addr").ToString
        txt_Name.Text = dr("cus_Name").ToString
    End While
    myConnection.Close()

Ошибка в dr = cmd.ExecuteReader ()

Dr объявлен как OleDbDataReader "