冒险岛豹弩白豹子:各位高手请帮忙"未将对象引用设置到对象的实例"

我想用引用datagrid(id为dg)中的子控件datagrid1(id为dg1)出现上面的错误的.

html中我设置了两个嵌套的datagrid控件.
下面这是程序代码:
<script language="vb" runat=server>
Sub Page_Load(sender As Object,e As EventArgs)
if not page.ispostback then
gridbind()
end if
End Sub
sub gridbind
dim conn as oledbconnection=new oledbconnection("provider=microsoft.jet.oledb.4.0;data source=" & System.Web.HttpContext.Current.Server.MapPath("luyan.mdb"))
conn.Open()
Dim da As New OleDbDataAdapter("select *from one",conn)
Dim ds As New DataSet
da.Fill(ds, "chy")
dg.DataSource = ds.Tables("chy")
dg.DataBind()
conn.close
end sub
sub repeater(ByVal sender As Object, ByVal e As datagridItemEventArgs)
dim conn1 as oledbconnection=new oledbconnection("provider=microsoft.jet.oledb.4.0;data source=" & System.Web.HttpContext.Current.Server.MapPath("luyan.mdb"))
conn1.Open()

Dim da1 As New OleDbDataAdapter("select *from two",conn1)

Dim ds1 As New DataSet

da1.Fill(ds1, "chy1")

Dim rep As DataGrid
rep=new datagrid
rep = e.Item.FindControl("dg1")
response.Write(rep)
rep.DataSource = ds1.tables("chy1")
rep.DataBind()
End Sub

</script>