The FIRST-CHILD attribute serves as a tool to query the first created child dialog element, that is, the dialog element one level below the (parent) dialog element. An example of such a child-parent relationship between dialog elements is the relationship between a dialog and several push button controls inside. With the FIRST-CHILD attribute, you query the push button control that has been created first inside the dialog. You use this attribute in conjunction with the SUCCESSOR attribute to "travel" through the hierarchy of dialog elements.

Applies to	Date/time picker control, dialogs (all types) and all dialog elements, image control, image list control, list view column, list view control, list view item, progress bar control, slider control, spin control, tree view control, tree view item.
Data Type	HANDLE
Default Value	NULL-HANDLE
Possible Values	NULL-HANDLE (no child existing) / any dialog element handle