/// <summary>Sends a session expiration event to the script
		/// instance that was triggered as a result of an incoming
		/// HTTP request.</summary>
		/// <param name="sessionKey">The routing GUID of the script instance.</param>
		[Event(IHttp.EVENT_SESSION_EXPIRED, eventTypeType.nontriggering, null, "HTTP Session Expired", "Fired when an HTTP session expires.")]
		public void SendExpiredSessionEvent(string sessionKey)
		{
			if(sessionKey == null) return;

			EventMessage sessionExpiredMsg = 
				CreateEventMessage(IHttp.EVENT_SESSION_EXPIRED, EventMessage.EventType.NonTriggering, sessionKey);

			sessionExpiredMsg.SuppressNoHandler = true;

			palWriter.PostMessage(sessionExpiredMsg);
		}