รบกวน VB 2008 ครายเขียน VB2008 ได้มั่งอ่ะ เขียน code รันเลข auto ไงคะ

    Function AutoNumber() As String

        Dim myAdapter As New MySqlDataAdapter("SELECT * FROM patient ORDER BY hn DESC", myconn)
        Dim myDataTable As New DataTable()
        myAdapter.Fill(myDataTable)
        Dim Count As Integer
        Dim NumID As String
        Count = (myDataTable.Rows.Count)
        If Count = 0 Then
            NumID = Mid(Year(Now) + 543, 3, 2) & "00001"


        Else
            If Mid(myDataTable.Rows(0)("hn"), 1, 2) = Mid(Year(Now) + 543, 3, 2) Then
                NumID = Mid(Year(Now) + 543, 3, 2) & (CInt(Mid(myDataTable.Rows(0)("hn"), 3, 5)) + 1).ToString("00000")

            Else
                NumID = Mid(Year(Now) + 543, 3, 2) & "00001"
            End If

        End If

        Return NumID
    End Function

me.Close()