On Check
The actions that will be performed whenever an item is checked/unchecked in a tree or listbox object.
ListBox - Note that clicking on an unselected checkbox in the list will trigger an On Select event before the On Check event is fired. This is the normal behaviour for checklist box controls in Windows. Specifically, clicking on a checkbox in the list toggles the check for all selected items. If the item is currently unselected, it is selected first, then the checkbox is toggled.
ListBox - Note: If the item is already selected, there will be no On Select event first. Do not depend on there being an On Select every time you toggle a check box.
The following event variables are automatically set whenever this event is triggered: (only available for the tree object).