how to make the vertices of a polygon not visible in JSXGraph

This is a beginner question. When I use board.create('polygon',[[0,0],[0,1],[1,1],[1,0]]), JSXgraph creates a polygon with vertices and border lines visible. I can hide the border with board.create('polygon',[[0,0],[0,1],[1,1],[1,0]],{withLines: false}), but I don't know how to hide the vertices. I see in the manual, that the attributes for the vertices can be changed, but I don't know the syntax how to do it. I can get around by defining the vertices as points separately and use the point names in the definition of the polygon, but I would prefer if the same could be achieved simply by adding something to the attribute list of the polygon. Any help would be appreciated.

Solution

There are essentially two possibilities:

set the visibility of the vertices directly by

     var board = JXG.JSXGraph.initBoard("jxgbox", {
                boundingbox: [-5, 5, 5, -5],
                axis: false
            });
      var pol = board.create('polygon',[[0,0],[0,1],[1,1],[1,0]], 
                  {vertices: {visible:false}});

.jxgbox {
    /* for IE 7 */
    position: relative;
    overflow: hidden;
    background-color: #ffffff;
    border-style: solid;
    border-width: 1px;
    border-color: #356AA0;
    border-radius: 10px;
    -webkit-border-radius: 10px;
    -ms-touch-action: none;
}

.JXGtext {
    /* May produce artefacts in IE. Solution: setting a color explicitly. */
    background-color: transparent;
    font-family: Arial, Helvetica, Geneva, sans-serif;
    padding: 0;
    margin: 0;
}

.JXGinfobox {
    border-style: none;
    border-width: 1px;
    border-color: black;
}

<script src="//cdnjs.cloudflare.com/ajax/libs/jsxgraph/0.99.5/jsxgraphcore.js"></script>
<div id="jxgbox" class="jxgbox" style="width:600px; height:600px;"></div>

set the visibility later:

var pol = board.create('polygon',[[0,0],[0,1],[1,1],[1,0]], 
             {vertices:  {visible:true}});
for (i = 0; i < pol.vertices.length - 1; i++) {
    pol.vertices[i].setAttribute({visible: false});
}