How to assign UpdatePanel Trigger's control ID with button's from gridview

Question

currently I have a UpdatePanel for jQuery Dialog use, which contains a GridView.

And that GridView contains a FileUpload control in footer and EmptyDataTemplate

Answer 1

This works

protected void grdExpense_RowCreated(object sender, GridViewRowEventArgs e)
    {
        LinkButton btnAdd = (LinkButton)e.Row.Cells[0].FindControl("btnAdd");
        if (btnAdd != null)
        {
            ScriptManager.GetCurrent(this).RegisterPostBackControl(btnAdd);
        }

    }