ContentValues attValues = new ContentValues();
attValues.put(CalendarContract.Attendees.ATTENDEE_NAME, "RRD Attendees");
attValues.put(CalendarContract.Attendees.ATTENDEE_EMAIL, "sample@gmail.com");
attValues.put(CalendarContract.Attendees.ATTENDEE_RELATIONSHIP, CalendarContract.Attendees.RELATIONSHIP_NONE);
attValues.put(CalendarContract.Attendees.ATTENDEE_TYPE, CalendarContract.Attendees.TYPE_REQUIRED);
attValues.put(CalendarContract.Attendees.ATTENDEE_STATUS, CalendarContract.Attendees.ATTENDEE_STATUS_INVITED);
attValues.put(CalendarContract.Attendees.EVENT_ID, eventID);
Uri uri = cr.insert(CalendarContract.Attendees.CONTENT_URI, attValues);