Add row at the footer of Editable Gridview

protected void GridView3_RowCommand(object sender, GridViewCommandEventArgs e)
{              
        if (e.CommandName == "Submit")
        {
            string prodid = ((TextBox)ddgrnstatus.FooterRow.FindControl("ProdId")).Text;
            string Dis_Id = ((TextBox)ddgrnstatus.FooterRow.FindControl("P_displayId")).Text;
            string ProdName = ((TextBox)ddgrnstatus.FooterRow.FindControl("ProductName")).Text;
            string MaxQty = ((TextBox)ddgrnstatus.FooterRow.FindControl("MaxQty")).Text;
            string MinQty = ((TextBox)ddgrnstatus.FooterRow.FindControl("MinQty")).Text;
            string ReorderQty = ((TextBox)ddgrnstatus.FooterRow.FindControl("ReorderQty")).Text;
            string Qtyonhand = ((TextBox)ddgrnstatus.FooterRow.FindControl("qtyonhand")).Text;       
        }
}