parentElement PropertyRetrieves the parent object in the object hierarchy.
sourceIndex PropertyRetrieves the ordinal position of the object, in source order, as the object appears in the all collection.
sourceIndex PropertyRetrieves the ordinal position of the object, in source order, as the object appears in the all collection.
<div id="dv"><div id="dv2">hello</div></div>
dv2's parentElement is dv, i.e.,
document.all("dv2").parentElement == document.all("dv")sourceIndex refers to the position in document.all collection for the current element, for example,
document.all("dv2").sourceIndex == document.all("dv").sourceIndex + 1