code: function(node, geometry, radius) {
          if(!isNaN(geometry.x)&& !isNaN(geometry.y)) {
              var resolution = this.getResolution();
  
              node.style.left = ((((geometry.x - this.featureDx) /resolution - this.offset.x) | 0) - radius) + "px";
              node.style.top = (((geometry.y /resolution - this.offset.y) | 0) - radius) + "px";
      
              var diameter = radius * 2;
              
              node.style.width = diameter + "px";
              node.style.height = diameter + "px";
              return node;
          }
          return false;
      }
docs: Method: drawCircle
  Render a circle.
  Size and Center a circle given geometry (x,y center) and radius
  
  Parameters:
  node - {DOMElement}
  geometry - {<OpenLayers.Geometry>}
  radius - {float}
  
  Returns:
  {DOMElement} or false if the circle could not ne drawn