protected void Calendar1_DayRender(object sender, DayRenderEventArgs e) { Details d = new Details(); long det = d.trainerdet(Session["adminlogin"].ToString()); TrainerDao calendar = new TrainerDaoSqlImpl(); List <model.Calender> trainerCal = new List <model.Calender>(); trainerCal = calendar.getDatesTrainer(det); foreach (var t in trainerCal) { DateTime date1 = t.StartDate; DateTime date2 = t.Enddate; string availability = t.Availability_status; if (e.Day.Date >= date1 && e.Day.Date <= date2 && availability == "Busy") { e.Cell.Attributes.Add("onclick", "javascript:alert('Busy')"); e.Cell.ForeColor = System.Drawing.Color.DarkRed; } else { e.Cell.Attributes.Add("onclick", "javascript:alert('Free')"); } } }