Can I assign an instance of a Movie clip to another existing Movieclip?

1

I have a problem with swapping Depths of movie clips. This may be related to what I am trying to do immediately before - assigning an existing movieclip instance to another movieclip instance. I.e. Using the trace for the depth of side5, it should always output 13, however, it does not always do this, sometimes it is 13, sometimes it is 10, etc. Anyone know of a better way to assign an existing movieclip instance to another existing movieclip instance?

_root[“side9”] = _root[“side8”];
_root[“side8”] = _root[“side7”];
_root[“side7”] = _root[“side6”];
_root[“side6”] = _root[“side5”];
_root[“side5”] = _root[“side4”];
_root[“side4”] = _root[“side3”];
_root[“side3”] = _root[“side2”];
_root[“side2”] = _root[“side1”];

_root[“side9”].swapDepths(17);
_root[“side8”].swapDepths(16);
_root[“side7”].swapDepths(15);
_root[“side6”].swapDepths(14);
_root[“side5”].swapDepths(13);
_root[“side4”].swapDepths(12);
_root[“side3”].swapDepths(11);
_root[“side2”].swapDepths(10);

trace(_root[“side5”].getDepth());