code: function timelineMouseDown(e) {
  
                  previousXPosition = e.clientX;
                  previousYPosition = e.clientY;
  
                  var chartAxes = existingChartRef.getAxes();
                  var timelineAxes = plot.getAxes();
                  var leftBoundVal = chartAxes.xaxis.min;
                  var rightBoundVal = chartAxes.xaxis.max;
                  var eventVal = timelineAxes.xaxis.c2p(e.clientX - plot.offset().left);
                  if ((eventVal < leftBoundVal || eventVal > rightBoundVal) && updateExistingChart) {
                      //Center chart on the click event.
                      if (existingChartRef == null) { return; }
                      var existingChartGetAxes = existingChartRef.getAxes();
                      var newPos = timelineAxes.xaxis.c2p(e.clientX - plot.offset().left);
                      var timePerDivision = (existingChartGetAxes.xaxis.max - existingChartGetAxes.xaxis.min) / 10;
                      var min = newPos - timePerDivision * 5;
                      var max = newPos + timePerDivision * 5;
                      existingChartGetAxes.xaxis.options.min = min;
                      existingChartGetAxes.xaxis.options.max = max;
                      existingChartRef.setupGrid();
                      existingChartRef.draw();
                      plot.updateTimelineCurtains({
                          min: min,
                          max: max
                      });
                  }
                  plot.getPlaceholder().bind('mousemove', horPanTimeline);
              }
docs: ************************************************************
  Event Functions
  ************************************************************