board hit event

HTML

<link rel="stylesheet" href="http://jsxgraph.uni-bayreuth.de/distrib/jsxgraph.css">
<script src="http://jsxgraph.uni-bayreuth.de/distrib/jsxgraphcore.js"></script>
<button onclick="changeColor()">
Butt
</button>
<div id='box' class='jxgbox'></div>

CSS

#box {
    width:500px;
    height:300px;
}

JavaScript

var brd = JXG.JSXGraph.initBoard('box', {axis: false, boundingbox: [-10, 10, 10, -10]});

var a = brd.create('point', [1, 2], {myInfoboxColor: 'blue'});
var b = brd.create('point', [-3, -2], {myInfoboxColor: 'red'});
var c = brd.create('point', [3, -1]);
var s = brd.create('line',[b,a]);

brd.on('hit', function (event, element) {
    if (JXG.isPoint(element)) {
        brd.infobox.setProperty({strokeColor: element.visProp.myinfoboxcolor || 'black'});
    }
});
function changeColor()
{
	b.fillColor="blue";
}