Dynamic Instance name vs manual Instance name?

programming flash
1

Hello,

I would like to access this object (taken from Debug > List Objects of in flash player)

 ActionScript Code:
 [LEFT][COLOR=#0000ff]Target[/COLOR]=[COLOR=#ff0000]"_level0.promotion0.loader_mc.instance87.promoTXT"[/COLOR]

[/LEFT]

This is what I am trying to access it with:

 ActionScript Code:
 [LEFT][COLOR=#0000ff]trace[/COLOR][COLOR=#000000]([/COLOR] [COLOR=#0000ff]this[/COLOR].[COLOR=#000080]getChildByName[/COLOR][COLOR=#000000]([/COLOR][COLOR=#ff0000]"promotion0"[/COLOR][COLOR=#000000])[/COLOR].[COLOR=#000080]loader_mc[/COLOR].[COLOR=#000080]getChildByName[/COLOR][COLOR=#000000]([/COLOR][COLOR=#ff0000]"instance87"[/COLOR][COLOR=#000000])[/COLOR].[COLOR=#000080]promoTXT[/COLOR].[COLOR=#0000ff]text[/COLOR] [COLOR=#000000])[/COLOR];

[/LEFT]

Error:

ActionScript Code:
[LEFT][COLOR=#000080]1119[/COLOR]: Access of possibly [COLOR=#0000FF]undefined[/COLOR] property loader_mc through a reference [COLOR=#0000FF]with[/COLOR] [COLOR=#0000FF]static[/COLOR] [COLOR=#0000FF]type[/COLOR] flash.[COLOR=#000080]display[/COLOR]:DisplayObject.

[/LEFT]

what is the correct way to do this?