title: How to get lat/lang/radius of center of circle that user draw
body: <p>I'm using this exmaple from <a href="https://developers.google.com/maps/documentation/javascript/examples/drawing-tools" rel="noreferrer">https://developers.google.com/maps/documentation/javascript/examples/drawing-tools</a> to enable user to choose a point and enable user to draw a circle around it.</p>
  
  <p>However, I need also to:</p>
  
  <ul>
  <li>get the lat/lang of center of circle that user draw.</li>
  <li>get the radius of circle.</li>
  <li><p>also the code allows user to draw more than one circle, if possible, I need to restrict user to draw only one circle, if user draw another circle, first circle should be removed.
  <pre><code>
  function initialize() {
    var mapOptions = {
      center: new google.maps.LatLng(-34.397, 150.644),
      zoom: 8
    };</p>
  
  <p>var map = new google.maps.Map(document.getElementById('map-canvas'),
      mapOptions);</p>
  
  <p>var drawingManager = new google.maps.drawing.DrawingManager({
      drawingMode: google.maps.drawing.OverlayType.MARKER,
      drawingControl: true,
      drawingControlOptions: {
        position: google.maps.ControlPosition.TOP_CENTER,
        drawingModes: [
          google.maps.drawing.OverlayType.MARKER,
          google.maps.drawing.OverlayType.CIRCLE,
          google.maps.drawing.OverlayType.POLYGON,
          google.maps.drawing.OverlayType.POLYLINE,
          google.maps.drawing.OverlayType.RECTANGLE
        ]
      },
      markerOptions: {
        icon: 'images/beachflag.png'
      },
      circleOptions: {
        fillColor: '#ffff00',
        fillOpacity: 1,
        strokeWeight: 5,
        clickable: false,
        editable: true,
        zIndex: 1
      }
    });
    drawingManager.setMap(map);
  }</p>
  
  <p>google.maps.event.addDomListener(window, 'load', initialize);
  </pre></code></p></li>
  </ul>