DataGrid paging not working (C#)

I can sort columns fine ,but i get an error when i try to do built in paging. I tried everything. My other Datagrid events work fine

Code:

 <asp:DataGrid id="ProductDataGrid" OnPageIndexChanged="PageChangeClicked" OnItemCommand="DetailsClicked" OnSortCommand="SortEventHandler" style="Z-INDEX: 101; LEFT: 69px; POSITION: absolute; TOP: 80px" runat="server" Width="273px" Height="558px" AllowSorting="True" AllowPaging="True" AutoGenerateColumns="False" Font-Names="Arial Unicode MS" PageSize="15">
                <AlternatingItemStyle BackColor="#CCFF66"></AlternatingItemStyle>
                <Columns>
                    <asp:ButtonColumn Text="Details" ButtonType="PushButton" HeaderText="FAQ Details"></asp:ButtonColumn>
                    <asp:BoundColumn DataField="product_id" SortExpression="Manufacturer DESC" HeaderText="Product ID">
                        <HeaderStyle Font-Size="Large" Font-Underline="True" Font-Names="Book Antiqua" HorizontalAlign="Center" VerticalAlign="Middle"></HeaderStyle>
                    </asp:BoundColumn>
                    <asp:BoundColumn DataField="Comments" HeaderText="Comments of power">
                        <HeaderStyle Font-Size="Large" Font-Underline="True" Font-Names="Book Antiqua" HorizontalAlign="Center" VerticalAlign="Middle"></HeaderStyle>
                    </asp:BoundColumn>
                </Columns>
            </asp:DataGrid>



protected void PageChangeClicked(object sender, DataGridPageChangedEventArgs e)
        {
            ProductDataGrid.CurrentPageIndex = e.NewPageIndex;
       
            SqlConnection conn = null;
            conn = new SqlConnection("worksfine");
       
            String sqlSelect = "SELECT * FROM surplus_inventory";
            SqlDataAdapter dAdapt = new SqlDataAdapter(sqlSelect,conn);
            DataSet      myDS = new DataSet();
            dAdapt.Fill(myDS,"surplus_inventory");
       
            ProductDataGrid.DataSource = myDS;
            ProductDataGrid.DataBind();
        }




Error:(happens when I click on next link)


Server Error in '/SurplusInventory' Application.
--------------------------------------------------------------------------------

Specified argument was out of the range of valid values.
Parameter name: index
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.ArgumentOutOfRangeException: Specified argument was out of the range of valid values.
Parameter name: index

Source Error:

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.  

Stack Trace:


[ArgumentOutOfRangeException: Specified argument was out of the range of valid values.
Parameter name: index]
   System.Web.UI.ControlCollection.get_Item(Int32 index) +2057582
   System.Web.UI.WebControls.TableCellCollection.get_Item(Int32 index) +24
   SurplusInventory.DisplaySelectList.DetailsClicked(Object sender, DataGridCommandEventArgs e) +60
   System.Web.UI.WebControls.DataGrid.OnItemCommand(DataGridCommandEventArgs e) +105
   System.Web.UI.WebControls.DataGrid.OnBubbleEvent(Object source, EventArgs e) +77
   System.Web.UI.Control.RaiseBubbleEvent(Object source, EventArgs args) +35
   System.Web.UI.WebControls.DataGridItem.OnBubbleEvent(Object source, EventArgs e) +117
   System.Web.UI.Control.RaiseBubbleEvent(Object source, EventArgs args) +35
   System.Web.UI.WebControls.LinkButton.OnCommand(CommandEventArgs e) +115
   System.Web.UI.WebControls.LinkButton.RaisePostBackEvent(String eventArgument) +163
   System.Web.UI.WebControls.LinkButton.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument) +7
   System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument) +11
   System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData) +174
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +5102