The LayoutStartChanging(exResizeChart) event notifies your application once the user starts resizing the chart. The LayoutEndChanging(exResizeChart) event notifies your application once the chart is resized. The ZoomHeight property specifies a value that indicates how large the chart will appear on vertical axis. Use the MinZoomWidth/MaxZoomWidth property to specify the limits on horizontal axis when the user performs resizing/zooming/shrinking. Use the MinZoomHeight/MaxZoomHeight property to specify the limits on horizontal axis when the user performs resizing/zooming/shrinking. The AllowResizeChart property specifies the combination of keys so the user can resize the chart at runtime,