property CalendarCombo.Locked as Boolean
Specifies whether the user can change the selection.

TypeDescription
Boolean A boolean expression that specifies whether the control is locked or unlocked. 
By default, the Locked property is False. Use the Locked property to lock the control. While the control is locked, the drop down portion of the control can be displayed, while the control is disabled, the control can't display it's drop down portion of the control. While locked the user can't change the selected date.