text: var points = new OpenLayers.Layer.PointGrid({
      isBaseLayer: true, dx: 15, dy: 15
  });
  
  var map = new OpenLayers.Map({
      div: "map",
      layers: [points],
      center: new OpenLayers.LonLat(0, 0),
      zoom: 2
  });
  
  var rotation = document.getElementById("rotation");
  rotation.value = String(points.rotation);
  rotation.onchange = function() {
      points.setRotation(Number(rotation.value));
  };
  
  var dx = document.getElementById("dx");
  var dy = document.getElementById("dy");
  dx.value = String(points.dx);
  dy.value = String(points.dy);
  dx.onchange = function() {
      points.setSpacing(Number(dx.value), Number(dy.value));
  };
  dy.onchange = function() {
      points.setSpacing(Number(dx.value), Number(dy.value));
  };
  
  var max = document.getElementById("max");
  max.value = String(points.maxFeatures);
  max.onchange = function() {
      points.setMaxFeatures(Number(max.value));
  };
  