anchor.diff:  
   
       mainChart.rows= await dailyValues(startDate.value,endDate.value,pair);
  +    mainChart.on['google-chart-select'].listen(sendMessage);
   
     }
   
  
positive.code:   }
    sendMessage(Event e)
    {
      window.alert(e.type);
    }
  
    loadChartDialog(Event e)
  
negative.code:   {
      String pair =currencyPairs[$['menuPair'].selected];
      mainChart = $['mainChart'];
  
  
      String chartTitle="Daily Rates for "+pair;
      var options = {
        'title':chartTitle,
  