protected string[] GetInvoiceValues(ParticipantBlock participant)
        {
            string[] values = GetInvoiceFields();
            for (int i = 0; i < values.Length; i++)
            {

                if (values[i] == "eventname")
                {
                    values[i] = GetCourseName(participant.EventPage) + " for " + GetFormData(participant, "firstname") + " " + GetFormData(participant, "lastname");
                }
                else
                values[i] = GetFormData(participant, values[i]);
            }
            return values;
        }
        public static Control GetSessionsControl(ContentReference currentEvent, ParticipantBlock participant)
        {
            var sessions = AttendSessionEngine.GetSessionsList(currentEvent);
            PlaceHolder ph = new PlaceHolder();

            foreach (AttendSessionEngine.Session session in sessions)
            {
                if (session.CheckBox)
                {

                    var cb = new CheckBox() { Enabled = session.Enabled, Checked = session.Selected };
                    cb.InputAttributes.Add("value", session.ContentID.ToString());
                    cb.InputAttributes.Add("name", session.Group);
                    ph.Controls.Add(cb);
                    ph.Controls.Add(new LiteralControl(session.Name + "<br/>"));
                }
                else
                {
                    if (session.NewGroup)
                        ph.Controls.Add(new LiteralControl("<br/>"));
                    var li = new RadioButton() { Enabled = session.Enabled, Checked = session.Selected, GroupName = session.Group };
                    li.InputAttributes.Add("value", session.ContentID.ToString());
                    li.InputAttributes.Add("name", session.Group);
                    ph.Controls.Add(li);
                    ph.Controls.Add(new LiteralControl(session.Name + "<br/>"));
                }
            }
            return ph;
        }