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Event Functions
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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);
            }