protected void Page_Load(object sender, EventArgs e) { if (!IsPostBack) { ProjectDataAccess obj = new ProjectDataAccess(); List <int> EmpIDList = obj.GetEmployeeID(); int i = 0; foreach (int EmpID in EmpIDList) { EmployeeIDDropDownList.Items.Insert(i, new ListItem(EmpID.ToString())); i++; } } UnobtrusiveValidationMode = UnobtrusiveValidationMode.None; }