gridview nested control value's?

<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False"
            class="grid" AllowSorting ="True"
            DataSourceID="SqlDataSource1"  ForeColor="#333333" Height="22px" Width="776px"

            BorderWidth="1px" BorderColor="#AAAAAA" CellPadding="2" CellSpacing="2"><Columns><asp:BoundField DataField="ProductId" HeaderText="ProductId"
                    SortExpression="ProductId" /><asp:TemplateField><ItemTemplate><span class="rate33"><asp:GridView ID="GridView7" runat="server" AllowSorting="True"
                            AutoGenerateColumns="False" BorderColor="#AAAAAA" BorderWidth="1px"
                            CellPadding="2" CellSpacing="2" ForeColor="#333333" Height="16px" PageSize="5"
                            ShowHeader="False" Width="109px"><AlternatingRowStyle BackColor="White" Font-Size="8pt" ForeColor="Black" /><Columns><asp:BoundField DataField="ID" HeaderText="Id" ReadOnly="True"
                                    SortExpression="ID" /><asp:BoundField DataField="Name" HeaderText="Name" SortExpression="Name" /><asp:BoundField DataField="AttributeControlTypeId"
                                    HeaderText="AttributeControlTypeId" SortExpression="AttributeControlTypeId" /><asp:TemplateField><ItemTemplate><asp:DropDownList ID="DropDownList1" runat="server"
                                            Font-Bold="True"
                                            OnLoad="Button1_Click"
                                            style="height: 40px" ViewStateMode="Enabled"></asp:DropDownList><asp:Label ID="SLabel1" runat="server" Text='<%# Bind("ID") %>'></asp:Label>
........................

 Protected Sub Button1_Click(sender As Object, e As EventArgs)
        Dim btn As DropDownList = DirectCast(sender, DropDownList)
       Dim item As DataControlFieldCell = DirectCast(btn.Parent, DataControlFieldCell)
        Dim ddl As DropDownList = DirectCast(item.FindControl("DropDownList1"), DropDownList)
        Dim label1 As Label = DirectCast(item.FindControl("Slabel1"), Label)

end sub

 Private Sub GridView1_RowDataBound(sender As Object, e As System.Web.UI.WebControls.GridViewRowEventArgs) Handles GridView1.RowDataBound
        If e.Row.RowType = DataControlRowType.DataRow Then

            Dim GridView7 As GridView = DirectCast(e.Row.FindControl("GridView7"), GridView)

            Dim s1 As String

            Dim SQLstr As String
            Dim sqlConn As New SqlConnection
            Dim SEarchsqlConn As New SqlConnection
            Dim strConn As String
            Dim reader As SqlDataReader
            Dim cmd As New SqlClient.SqlCommand
              strConn = System.Configuration.ConfigurationManager.ConnectionStrings("JC").ConnectionString
            sqlConn = New SqlConnection(strConn)
            SEarchsqlConn = New SqlConnection(strConn)
            cmd.Connection = sqlConn
            Dim ds As New DataSet()
            sqlConn.Open()
            Dim productid As Integer = Convert.ToInt32(e.Row.Cells(0).Text)
            SQLstr = "SELECT ........ WHERE Variant_ProductAttribute_Mapping.ProductId =" & productId
            Dim adapter3 As SqlDataAdapter = New SqlDataAdapter(SQLstr, sqlConn)
            adapter3.Fill(ds, "Varaints")
            GridView7.DataSource = ds.Tables("Varaints")
            GridView7.DataBind()
            sqlConn.Close()



         
        End If

Hi I have 2 gridview nested and Im not able to get the Slabel value? in the button1 click. appreciate any help!