if(!db || !parentFolderElement || !folderElement)
if(!db || !parentResource || !deletedFolderResource)
NS_IMETHODIMP nsMessenger::DeleteFolders(nsIRDFCompositeDataSource *db, nsIDOMXULElement *parentFolderElement,							nsIDOMXULElement *folderElement){	nsresult rv;	if(!db || !parentFolderElement || !folderElement)		return NS_ERROR_NULL_POINTER;	nsCOMPtr<nsISupportsArray> parentArray, deletedArray;	nsCOMPtr<nsIRDFResource> parentResource, deletedFolderResource;	rv = parentFolderElement->GetResource(getter_AddRefs(parentResource));	if(NS_FAILED(rv))		return rv;	rv = folderElement->GetResource(getter_AddRefs(deletedFolderResource));	if(NS_FAILED(rv))		return rv;	rv = NS_NewISupportsArray(getter_AddRefs(parentArray));	if(NS_FAILED(rv))	{		return NS_ERROR_OUT_OF_MEMORY;	}	rv = NS_NewISupportsArray(getter_AddRefs(deletedArray));	if(NS_FAILED(rv))	{		return NS_ERROR_OUT_OF_MEMORY;	}	parentArray->AppendElement(parentResource);	deletedArray->AppendElement(deletedFolderResource);	rv = DoCommand(db, NC_RDF_DELETE, parentArray, deletedArray);	return NS_OK;}