.NET รบกวนช่วยดู Error นี้ทีครับ เพิ่งเขียน VB.net นะครับ

Imports System.Data
Imports System.Data.OleDb
Imports System.Xml
Imports CrystalDecisions.CrystalReports.Engine

Public Class FrmMain

    Private Sub FrmMain_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

        Dim MyConnection As New OleDbConnection

        MyConnection.ConnectionString = ("Provider=IBMDA400.DataSource.1;" & _
        "Data Source=10.1.1.101;User ID=ABC;Password=ABC;" & _
        "SSL=DEFAULT")

        'Open the connection         
        MyConnection.Open()

        Dim objConn As New OleDbConnection
        Dim dtAdapter As OleDbDataAdapter
        Dim objCmd As OleDbCommand
        Dim strSQL As String
        Dim dt1 As DataTable
        Dim ds As New DataSet


        fr_inv.Text = "12001915"
        to_inv.Text = "12001915"

        strSQL = "Select SICUST,SIINVN,SIINVD,SIORD,SITERM,SIQTY,EXRTE,ILPROD,IHDPFX,IHDOCN  " & _
             "from BPCSF524.sih t1 " & _
             "left outer join BPCSF524.sil t2 " & _
             "on t1.IHDPFX = t2.ILDPFX " & _
             "and t1.IHDOCN = t2.ILDOCN " & _
             "left outer join BPCSF524.EXRTE1 t3 " & _
             "on  substring(SIINVD,1,2) = t3.EXYEAR " & _
             "and substring(SIINVD,3,2) = t3.EXMON " & _
             "WHERE t1.IHDOCN  >= '" + fr_inv.Text + "' " & _
             "and   t1.IHDOCN  <= '" + to_inv.Text + "' " & _
             "and   substring(t2.ILPROD,1,2) <> 'FM' " & _
             "order by IHDPFX,IHDOCN,ILPROD"

        objCmd = New OleDbCommand(strSQL, MyConnection)
        dtAdapter = New OleDbDataAdapter(strSQL, MyConnection)
        dtAdapter.Fill(ds, "Mytable")
        dt1 = ds.Tables(0)
        DataGridView1.DataSource = ds.Tables(0)
        'dtAdapter = Nothing
        MyConnection.Close()

        'Excel

        Dim strConnString As String
        Dim dsex1 As New DataSet
        Dim dt2 As New DataTable
        Dim dc As New DataColumn
        strConnString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=D:\DataUser\Data_laos.xls;" & _
        "Extended Properties=Excel 8.0;"
        objConn.ConnectionString = strConnString
        objConn.Open()

        strSQL = "Select CUSID,CUSADDR,CUSTEL,CUSEMP FROM [Name$] "

        objCmd = New OleDbCommand(strSQL, objConn)
        dtAdapter = New OleDbDataAdapter(strSQL, objConn)


        ' fill dataset 
        dtAdapter.Fill(ds, "MyName")
        dt2 = ds.Tables(0)
        dtAdapter = Nothing
        objConn.Close()


        ds.Merge(dt2)
        DataGridView2.DataSource = ds.Tables(0)

        Dim relation As DataRelation
        Dim table1Column As DataColumn
        Dim table2Column As DataColumn
        'retrieve column
        table1Column = ds.Tables("Mytable").Columns("SICUST")

        table2Column = ds.Tables("MyName").Columns("CUSID")

        'relating tables 
        ' Error ตรงนี้ครับ
        relation = New DataRelation("relation", table1Column, table2Column)        
        'assign relation to dataset
        ds.Relations.Add(relation)


        TxtYr.Text = Year(Today) - 543
        Cmb_Show.SelectedIndex = Month(Today) - 1
        fr_inv.Select()

    End Sub