function Publisher() {
	var m_subscribers=new Array();
	
	this.addSubscriber=addSubscriber;
	this.removeSubscriber=removeSubscriber;
	this.notifySubscribers=notifySubscribers;

	function addSubscriber(subscriber,eventType){
		for(var i=0;i<m_subscribers.length;i++){
			if((m_subscribers[i][0]==subscriber)
			   &&(m_subscribers[i][1]==eventType)){
				return(false);
			}
		}
		var entryDetails=new Array();
		entryDetails[0]=subscriber;
		entryDetails[1]=eventType;
		m_subscribers[m_subscribers.length]=entryDetails;
		return(true);
	}
	function removeSubscriber(subscriber,eventType){
		for(var i=0;i<m_subscribers.length;i++){
			if((m_subscribers[i][0]==subscriber)
			  &&(m_subscribers[i][1]==eventType)){
				m_subscribers.splice(i,1);
			}
		}
	}
	function notifySubscribers(publisher,eventType,addInfo){
		for(var i=0;i<m_subscribers.length;i++){
			if(m_subscribers[i][1]==eventType){
				m_subscribers[i][0](publisher,eventType,addInfo);
			}
		}
	}
}