A SelectOnEnum expression that indicates whether the control selects an item
when user presses or releases the mouse button.
Use the SelectOn property to specify when the control
selects an item. By default, the SelectOn property is exMouseDown. If the
SelectOn property is exMouseUp the control selects an item only when the user
releases the mouse button. Use the SelectOn property on exMouseUp, when
controls under the drop down portion of the menu fire MouseUp events. The
control fires the Select event when an
item is selected.