nsresult rv = aContent->GetParent(*getter_AddRefs(parent));
nsresult rv = aContent->GetParent(getter_AddRefs(parent));
ContentToParentOffset(nsIContent *aContent, nsIDOMNode **aParent, PRInt32 *aOffset){  if (!aParent || !aOffset)    return;  *aParent = nsnull;  *aOffset  = 0;  if (!aContent)    return;  nsCOMPtr<nsIContent> parent;  nsresult rv = aContent->GetParent(*getter_AddRefs(parent));  if (NS_FAILED(rv) || !parent)    return;  rv = parent->IndexOf(aContent, *aOffset);  if (NS_FAILED(rv))    return;  CallQueryInterface(parent, aParent);}