Determines the parent handle of a dialog or a dialog element in the hierarchy. At the top of the hierarchy are one or several base dialogs; these are the parents of the dialog elements contained in them. These children may themselves contain children, such as controls in a child dialog. Children on the same level are called siblings. They may be enumerated using the SUCCESSOR attribute with the same parent.

The parent/child relationship can only be changed by "deleting" a child and creating a new one.

Applies to	Date/time picker control, dialogs (all types) and all dialog elements, dialog bar control, image control, image list control, list view column, list view control, list view item, tab control, tab control tab, progress bar control, slider control, spin control, tree view control, tree view item, wallpaper control.
Data Type	HANDLE
Default Value	NULL-HANDLE
Possible Values	NULL-HANDLE / any dialog element