This event is generated whenever the user clicks on the vertical scrollbar. Use this event to perform operations specific to whenever a vertical scroll is performed.
If Y-Stacking is being used, the chart will display more than one plot area, with each plot having its own vertical scrollbar.
The parameter passed along with this event is described below.
|Index||A value greater than 0 indicates the graph's y-stacked index. Y-stacked graphs are drawn with index 1 at the top, then index 2, and so on.|