title: Highcharts - highlight mouse position within a range
body: <p>I need to highlight mouse position when mouse is within a xAxis range of a line chart in HIighCharts. 
  I want to display a circle to highlight the mouse position. But I want this functionality only for the last 25 xAxis values.</p>
  
  <p>Is it possible to do this in Highcharts? </p>
  
  <p>One way is by following code but it has its limitations:</p>
  
  <pre><code>var circle = chart.renderer.circle(0, 0, 5).attr({
      fill: 'blue',
      stroke: 'black',
          'stroke-width': 1
  }).add()
      .toFront()
      .hide();
  
  $(chart.container).mousemove(function (event) {
          circle.attr({
              x: event.offsetX,
              y: event.offsetY
          });
          if (event.offsetX &gt; SOME_VALUE) circle.show();
      });
  </code></pre>
  
  <p>The shortcomings are that I am comparing event.offsetX instead of event.xAxis[0].value i.e. I am comparing the xValue of mouse in page rather than xAxis value in chart.</p>
  
  <p>Thanks in advance</p>