mFrameSelection = aList;
mFrameSelection = nsnull;
nsDOMSelection::nsDOMSelection(nsSelection *aList){  mFrameSelection = aList;  mFixupState = PR_FALSE;  mDirection = eDirNext;  NS_NewISupportsArray(getter_AddRefs(mRangeArray));  mScriptObject = nsnull;  mAutoScrollTimer = nsnull;  NS_NewISupportsArray(getter_AddRefs(mSelectionListeners));  NS_INIT_REFCNT();}