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); } }