if (dt1.Rows.Count == 0)
        {
            dt1.Columns.Add("cid", Type.GetType("System.Int32"));
            dt1.Columns.Add("CourseName", Type.GetType("System.String"));
            dt1.Columns.Add("Trainer", Type.GetType("System.String"));
            dt1.Columns.Add("FromDate", Type.GetType("System.DateTime"));
            dt1.Columns.Add("ToDate", Type.GetType("System.DateTime"));
            dt1.Columns.Add("EventForeColor", Type.GetType("System.String"));
            dt1.Columns.Add("EventBackColor", Type.GetType("System.String"));
            for (i = 0; i < dt.Rows.Count; i++)
            {
                dr1 = dt1.NewRow();
                dr = dt.Rows[i];
                dr1["cid"] = dr["int_cid"].ToString();
                dr1["CourseName"] = dr["vch_coursenm"].ToString();
                dr1["Trainer"] = dr["vch_trainer"].ToString();
                dr1["FromDate"] = dr["dt_fromdt"].ToString();
                dr1["ToDate"] = dr["dt_todt"].ToString();
                dr1["EventForeColor"] = "orange";
                dr1["EventBackColor"] = "";
                dt1.Rows.Add(dr1);
            }
        }
        return dt1;
 Calendar1.EventStartDateColumnName = "FromDate";
            Calendar1.EventEndDateColumnName = "ToDate";
            Calendar1.EventDescriptionColumnName = "Trainer";
            Calendar1.EventHeaderColumnName = "EventBackColor";
            Calendar1.EventBackColorName = "EventBackColor";
            Calendar1.EventForeColorName = "EventForeColor";
            Calendar1.EventSource = dt1;