protected void fill_period()
        {
            DataTable dt3 = bus.fetch_period();

            if (dt3.Rows.Count > 0)
            {
                ddlper.DataSource = dt3;
                ddlper.DataBind();
                ddlper.Items.Insert(0, new ListItem("-----SELECT-----", ""));
            }
            else
            {
                ScriptManager.RegisterStartupScript(this, GetType(), "displayalertmessage", "warning();", true);
            }
        }