property Chart.OverviewLevelLines as Long
Indicates the index of the level that displays the grid line in the chart's overview.

TypeDescription
Long A long expression that indicates the index of the level that displays the grid lines in the chart's overview area.  
By default, the OverviewLevelLines property is -1. If the OverviewLevelLines property is -1, or indicates a non-existent level, no grid lines are shown in the chart's overview area. Use the OverviewLevelLines property to show grid lines in the chart's overview area. The OverviewVisible property shows or hides the chart's overview area. Use the Level property to access a level using its index. The LevelCount property indicates the number of levels being displayed in the control's header. Use the DrawGridLines property to specify the color of the grid lines in the overview area.