title: Find X(item) by click jfreechart
body: <p>I have <code>XYdataset</code> for plot time series.
  I need find the item number on X axis just by click on chart.
  below lines get item on X axis just when I click on series and if click on empty area in chart it return null. I need just item(X) not Y where ever I click on series or empty area in chart. is it possible to get this?
  Thanks for help</p>
  
  <pre><code>        //----------------------------------------------------------------------
          CP.addChartMouseListener(new ChartMouseListener() {
  
          @Override
          public void chartMouseClicked(ChartMouseEvent cme) {
              ChartEntity entity = cme.getEntity();   
              if (entity != null) {   
                  System.out.println("Mouse clicked: " + entity.toString());   
              }   
              else {   
                  System.out.println("Mouse clicked: null entity."+entity);   
              }   
          }
          @Override
          public void chartMouseMoved(ChartMouseEvent cme) {
  
          }
          //----------------------------------------------------------------------
  </code></pre>