title: If a point is clicked then add a marker in highcharts
body: <p>I want to add a maker when a point is clicked same like alerting a selected point...the code for selecting a point :</p>
  
  <pre><code>cursor: 'pointer',
              events: {
                  click: function(event) {
                      alert('x: ' + event.xAxis[0].value+' y: '+event.yAxis[0].value);
                  }
              }},
  </code></pre>
  
  <p>Now what should I write in place of alert to mark the point when it is clicked?</p>