Event which is raised when a change has been made to the workbook that might require a save. Note: This event is invoked asynchronously with regards to the change(s) that have occurred. Also some changes alone are not considered to dirty the Workbook even though it does change state on the Workbook or one of its subobjects. An example of that would be a zoom type operation (e.g. changing the magnificationInNormalView). Function takes arguments evt and ui. Use ui.owner to obtain reference to igSpreadsheet.
Target Platforms: Windows 8.1, Windows 8.1, Windows 8, Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2
