function node(PKey,nodeText) {
	// private vars
	var m_PKey=PKey;
	var m_displayDom=document.createElement("span");
	var m_nodeRelations=new Array();
	var m_toolbar=null;
	var m_textControl=null;
	var m_iconControl=null;
	var m_contextMenu=null;
	var m_isCollapsed=false;

	if (arguments.length >= 1) {
		return(construct());
	} else {
		this.fromXML=fromXML;
		return(this);
	}

	// properties
	function getPKey() { return(m_PKey); }
	function getNodeRelations() { return(m_nodeRelations); }

	// methods
	function construct() {
		// the basic node
		m_displayDom.setAttribute("id","mmNode_" + m_PKey);
		m_displayDom.setAttribute("class","node");
		m_displayDom.extends(new Publisher());
		dragNDrop.activateForObject(m_displayDom);
		
		m_contextMenu=addContextMenu();
		m_displayDom.appendChild(m_contextMenu);

		exportFunctions();

		// add a toolbar
		if (!m_toolbar) { 
			m_toolbar=new toolbar(m_displayDom); 
			m_displayDom.appendChild(m_toolbar);
			m_toolbar.hide();
		}
		
		if (!m_textControl){ m_textControl=new textControl(nodeText); }
		m_displayDom.appendChild(m_textControl);
		m_textControl.addSubscriber(notifyTextUpdate,"changeMode");
		
		if (!m_iconControl) {
			m_iconControl=new iconControl();
		}
		//m_displayDom.appendChild(document.createElement("br"));
		m_displayDom.appendChild(m_iconControl);

		if (m_isCollapsed) {collapse();}

		m_displayDom.onmouseup=mouseUpHandler;		
		m_displayDom.onmouseover=mouseOverHandler;
		m_displayDom.onmouseout=mouseOutHandler;

		document.getElementById('nodes').appendChild(m_displayDom);
		
		m_textControl.focus();
		return(m_displayDom);
	}
	function addContextMenu(){
		var contextMenu;
		var mi=new Array();
		for (var i=0;i<g_iconList.childNodes.length;i++) {
			var iconName=g_iconList.childNodes[i].getAttribute("filename");
			var iconTitle=g_iconList.childNodes[i].getAttribute("description");
			mi[mi.length]=new pictureMenuItem("icons/" + iconName ,iconTitle,onAddIconClick,"nodeIconMenuItem");
		} 
		//mi[mi.length]=new textMenuItem("Close",contextMenu.hide,"nodeContextMenuItem");
		contextMenu=new menuControl(mi,5);
		contextMenu.setAttribute("class","nodeContextMenu");
		contextMenu.hide();
                document.addSubscriber(contextMenu.hide,"clicked");

		m_displayDom.onmousedown=function(event) {contextMenuOpenAction(event);dragNDrop.onMouseDownHandler(event);}
		dragNDrop.addSubscriber(contextMenu.hide,"moving");
		function contextMenuOpenAction(event){
			if (event.target==m_displayDom) {
				contextMenu.toggleVisible();
				contextMenu.style.position="absolute";
				contextMenu.style.left=(event.clientX+window.scrollX-m_displayDom.style.left.split("px")[0]) + "px";
				contextMenu.style.top=(event.clientY+window.scrollY-m_displayDom.style.top.split("px")[0]) + "px";
			}
		}

		function onAddIconClick(event){
			m_iconControl.addIcon(event.target.getAttribute("src"));
		}
		return(contextMenu);
	}

	function exportFunctions(){
		m_displayDom.debugOut=debugOut;	
		m_displayDom.addNodeRelation=addNodeRelation;
		m_displayDom.deleteNodeRelation=deleteNodeRelation;
		m_displayDom.getPKey=getPKey;	
		m_displayDom.getNodeRelations=getNodeRelations;	
		m_displayDom.redrawNodeRelations=redrawNodeRelations;
		m_displayDom.hide=hide;
		m_displayDom.show=show;
		m_displayDom.collapse=collapse;
		m_displayDom.expand=expand;
		m_displayDom.erase=erase;
		m_displayDom.isCollapsed=isCollapsed;
		m_displayDom.isLeafNode=isLeafNode;
		m_displayDom.getParentNode=getParentNode;
		m_displayDom.getParentNodeRelation=getParentNodeRelation;
		m_displayDom.isChildNodeOf=isChildNodeOf;
		m_displayDom.isRootNode=isRootNode;

		m_displayDom.toXML=toXML;
		m_displayDom.fromXML=fromXML;
	}
	function notifyTextUpdate(publisher,eventType){
		redrawNodeRelations();
	}
	function mouseUpHandler(){
		redrawNodeRelations();
	}
	function mouseOverHandler(){
		m_displayDom.notifySubscribers(m_displayDom,"mouseOver");
		m_toolbar.show();
	}
	function mouseOutHandler(){
		m_displayDom.notifySubscribers(m_displayDom,"mouseOut");
		m_toolbar.hide();
	}
	function isCollapsed(){
		return(m_isCollapsed);
	}
	function getParentNodeRelation(){
		for (var i=0;i < m_nodeRelations.length;i++) {
			if ((m_nodeRelations[i].getChildNode()==m_displayDom) && (m_nodeRelations[i].isMain())){
				return(m_nodeRelations[i]);
			}
		}
		return(null);
	}
	function getParentNode(){
		var parentNode=getParentNodeRelation();
		if (parentNode) {
			return(parentNode.getParentNode());
		} else {
			return(null);
		}
	}
	function isChildNodeOf(testNode){
		var parentNode=getParentNode();
		if (parentNode){
			if (parentNode==testNode) {
				return(true);
			} else {
				return(parentNode.isChildNodeOf(testNode));
			}
		} else {
			// hit rootnode
			return(false);
		}
	}
	function isLeafNode(){
		for (var i=0;i < m_nodeRelations.length;i++) {
			if (m_nodeRelations[i].getParentNode()==m_displayDom){
				return(false);
			}
		}
		return(true);
	}
	function expand(isNonRecursive){
		m_isCollapsed=false;
		m_displayDom.setAttribute("class","node");
		for (var i=0;i < m_nodeRelations.length;i++) {
			if ((m_nodeRelations[i].isMain()) 
			   && (m_nodeRelations[i].getParentNode()==m_displayDom)){
				if (!isNonRecursive) { m_nodeRelations[i].getChildNode().expand(isNonRecursive); }
				m_nodeRelations[i].getChildNode().show();
			}
		}
	}
	function erase(){
		// first delete all free relations
		for (var i=m_nodeRelations.length-1;i>=0;i--) {
			if (!m_nodeRelations[i].isMain()) {
				var nodeRel=m_nodeRelations[i];
				deleteNodeRelation(nodeRel);
				nodeRel.erase();
			}
		}
		for (var i=m_nodeRelations.length-1;i>=0;i--) {
			// recursively delete childs following the Main-Links
			if (m_nodeRelations[i].getParentNode()==m_displayDom) {
				m_nodeRelations[i].getChildNode().erase();
				
			} 
		}
		// delete the relation to the parent
		for (var i=0;i < m_nodeRelations.length;i++) {
			if (m_nodeRelations[i].getChildNode()==m_displayDom){
				m_nodeRelations[i].erase();
			}
		}
		removeFromRootNodes();
		destroy();
	}
	function isRootNode(){
		for (var i=0;i < rootNode.length;i++) {
			if (m_displayDom==rootNode[i]) {
		        	return(true);
			}
		}
		return(false);
	}
	function removeFromRootNodes(){
		// remove current node from the rootnodes	
		for (var i=0;i < rootNode.length;i++) {
			if (m_displayDom==rootNode[i]) {
		        	rootNode.splice(i,1);
			}
		}
	}
	function destroy(){
		m_displayDom.parentNode.removeChild(m_displayDom);
	}

	function collapse(){
		m_isCollapsed=true;
		if (!isLeafNode()) { m_displayDom.setAttribute("class","collapsedNode"); }
		for (var i=0;i < m_nodeRelations.length;i++) {
			if ((m_nodeRelations[i].isMain()) 
			   && (m_nodeRelations[i].getParentNode()==m_displayDom)){
				m_nodeRelations[i].getChildNode().collapse();
				m_nodeRelations[i].getChildNode().hide();
			}
		}
	}

	function hide(){
		m_displayDom.style.display="none";
		for (var i=0;i < m_nodeRelations.length;i++) {
				m_nodeRelations[i].hide();
		}
	}

	function show(){
		m_displayDom.style.display="block";
		for (var i=0;i < m_nodeRelations.length;i++) {
				m_nodeRelations[i].show();
		}
		redrawNodeRelations();
	}

	function addNodeRelation(newNodeRel) {
		if (!hasNodeRelation(newNodeRel)) {
			m_nodeRelations[m_nodeRelations.length]=newNodeRel;
			if ((newNodeRel.getChildNode) && (newNodeRel.getChildNode()==m_displayDom) && (newNodeRel.isMain())) {
				removeFromRootNodes();
			}
		}
	}
	function deleteNodeRelation(nodeRel) {
		for (var i=0;i<m_nodeRelations.length;i++) {
			if (m_nodeRelations[i]==nodeRel) {
				m_nodeRelations.splice(i,1);
			}
		}
	}
	function hasNodeRelation(nodeRel) {
		for (var i=0;i<m_nodeRelations.length;i++) {
			if (m_nodeRelations[i]==nodeRel) {
				return(true);
			}
		}
	}
	function debugOut() {
		var output=("PKey: _"+ m_PKey + "_");
		output=output +	"\nRootNode: " + isRootNode();
		output=output +	"\nLeafNode: " + isLeafNode();
		output=output +	"\nNodeText: " + m_textControl.getText();
		output=output +	"\nisCollapsed: " + m_isCollapsed;
		output=output + "\nNodeRelations:";
		for (i=0;i < m_nodeRelations.length;i++) {
			output=output + m_nodeRelations[i].debugOut();
		}
		return(output);
	}     

	function redrawNodeRelations(){
		var rels=getNodeRelations();
		var i;
		for (i=0;i<rels.length;i++) {
			rels[i].redraw();
		}
	}

	function toXML(){
		var xmlEle=document.createElement("NODE");
		xmlEle.setAttribute("pkey",m_PKey);
		xmlEle.setAttribute("offsetleft",m_displayDom.style.left.split("px")[0]);
		xmlEle.setAttribute("offsettop",m_displayDom.style.top.split("px")[0]);
		xmlEle.setAttribute("iscollapsed",m_displayDom.isCollapsed());
		xmlEle.appendChild(m_textControl.toXML());
		xmlEle.appendChild(m_iconControl.toXML());
		
		var rels=getNodeRelations();

		for (var i=0;i<rels.length;i++){
			if (rels[i].getParentNode()==m_displayDom){
				xmlEle.appendChild(rels[i].toXML());
			}
		}
		
		return(xmlEle);
	}

	function fromXML(inXML){
		if (inXML.nodeName.toUpperCase()=="NODE") {
			m_PKey=inXML.getAttribute("pkey");
			m_displayDom.style.left=inXML.getAttribute("offsetleft")+"px";
			m_displayDom.style.top=inXML.getAttribute("offsettop")+"px";
			m_isCollapsed=inXML.getAttribute("iscollapsed")=="true";
			var freeRelations = new Array();
			for (var i=0;i<inXML.childNodes.length;i++){
				var theChildNode=inXML.childNodes[i];
				switch(theChildNode.nodeName.toUpperCase()){
					case "ICONS":
						m_iconControl=new iconControl().fromXML(theChildNode);
						break;
					case "TEXTCONTROL":
						m_textControl=new textControl().fromXML(theChildNode);
						break;
					case "NODEREL":
						construct();
						// only main relations handled here
						if (theChildNode.getAttribute("relationtype") == "main") {
							var newNodeRel=new nodeRel().fromXML(theChildNode);
							addNodeRelation(newNodeRel);
							newNodeRel.redraw();
						}
						break;
				}
			}
			return(construct());
		}
	}
}