add linkbutton to ajaxified radgrid header

[Morgan]

I have followed the code snippets from other posts on this issue to add a linkbutton to the group headers of my radgrid but on clicking the linkbutton's I get an object not specified error.

I'm adding the following code, where item is the gridgroupheaderitem and then handling the command in the radgrid_itemcommand event.
the code is added in both the radgrid_itemcreated and radgrid_itemdatabound events.

protected void RadGrid2_ItemDataBound(object sender, GridItemEventArgs e)
    {
        if (e.Item is GridGroupHeaderItem)
        {
            createbutton((GridGroupHeaderItem)e.Item);

        }
    }
    protected void createbutton(GridGroupHeaderItem header)
    {
        if (header.DataCell.FindControl("thisGroup") == null)
        {
            Label mylab = new Label();
            mylab.ID = "thisNumber";
            DataRowView drv = header.DataItem as DataRowView;
            mylab.Text = drv["Location"].ToString();
            Label mylabno = new Label();
            mylab.ID = "thisGroup";

            mylabno.Text = drv["GroupOrder"].ToString();
            mylabno.Visible = false;
            GridGroupHeaderItem item = header as GridGroupHeaderItem;
            LinkButton lnk = new LinkButton();
            lnk.Text = "Move up ";
            lnk.Style.Add("margin", "3px");
            LinkButton xnk = new LinkButton();
            xnk.Text = "Move down";
            xnk.Style.Add("margin", "2px");
            xnk.Style.Add("padding", "2px");

            item.DataCell.Controls.Add(mylab);
            item.DataCell.Controls.Add(mylabno);
            lnk.CommandName = "Up";
            item.DataCell.Controls.Add(lnk);
            xnk.CommandName = "Down";
            item.DataCell.Controls.Add(xnk);
        }
    }

I'm guessing its related to the fact this radgrid is ajaxified, but not entirely sure.  any ideas??

[Morgan]

Update: I've tried adding these buttons via the group header template in the radgrid, and same error occurs.
Sys.WebForms.PageRequestManagerServerErrorException: Object reference not set to an instance of an object.

[Morgan]

Sorted:  the answer was to put the buttons in the group header template and wire them up using click events not the commandname argument. 

thanks for looking.