property Pivot.PaneHeight(Bottom as Boolean) as Long
Specifies the height for the top or bottom panel.

Bottom as Boolean A Boolean expression that specifies part to be changed. 
Long A Long expression that specifies the height of the panel.
Use the PaneHeight property to specify the height on the top or bottom. The top panel is the control's pivot bar, while the bottom part is the control's list where the result goes. If the exPivotBarSizable is present in the PivotBarVisible property, the user can resize the pivot bar by dragging the bottom side of the control. The resize cursor is shown when the pivot bar is resizable and cursor hovers the bottom side of the pivot bar. The PaneMinHeight property specifies the minimum height of the top/bottom parts.