//tonen van een layer met extra informatie
function showExtraInfo( obj, layer, text ){
	layerDoc = document.getElementById( layer );
	
	layerDoc.innerHTML = text;	

	var curleft = curtop = 0;
	if (obj.offsetParent) {
		curleft = obj.offsetLeft
		curtop = obj.offsetTop
		while (obj = obj.offsetParent) {
			curleft += obj.offsetLeft
			curtop += obj.offsetTop
		}
	}
	//return [curleft,curtop];
	//alert("["+curleft+","+curtop+"]");
	layerDoc.style.left=(curleft+130)+"px";
	layerDoc.style.top=(curtop-10)+"px";
	layerDoc.style.display="block";

}

//verbergen van een layer
function hideExtraInfo( layer ){
	layerDoc = document.getElementById( layer );
	
	layerDoc.style.display = "none";
}