Urgent - Export movieclip as swf

I've tried to publish a single movieClip and that works but there's a problem that some value "const SHAPE_CHARACTER_ID:uint = 1;" I couldn't understand what it is or how it works! you've to write it manually like: 1, 3, 5.. to select the object that you want to publish it..

import com.codeazur.as3swf.SWF;

import com.codeazur.as3swf.SWFData;

import com.codeazur.as3swf.tags.TagDefineShape;

import com.codeazur.as3swf.tags.TagFileAttributes;

import com.codeazur.as3swf.tags.TagFrameLabel;

import com.codeazur.as3swf.tags.TagPlaceObject;

import com.codeazur.as3swf.data.SWFMatrix;

import com.codeazur.as3swf.tags.TagShowFrame;

import com.codeazur.as3swf.tags.TagEnd;

var my_mc1:MovieClip = new mc1();

addChild(my_mc1);

var my_mc2:MovieClip = new mc2();

my_mc2.x = 150;

addChild(my_mc2);

var my_mc3:MovieClip = new mc3();

my_mc3.x = 250;

addChild(my_mc3);

// to publish the first mc "my_mc1" use 1, "my_mc2" use 3, "my_mc3" use 5:

generateSWF(3, "demo.swf");

function generateSWF(SHAPE_CHARACTER_ID:uint, fileName:String)

{

     var swf: SWF = new SWF(loaderInfo.bytes);

     var shape: TagDefineShape = swf.getCharacter(SHAPE_CHARACTER_ID) as TagDefineShape;

     var swfTemp: SWF = new SWF();

     swfTemp.tags.push(shape);

// This tells the Flash Player to actually place the shape on the display list

     var placeObject: TagPlaceObject = new TagPlaceObject();

    placeObject.characterId = SHAPE_CHARACTER_ID;

    placeObject.depth = 1;

    placeObject.matrix = new SWFMatrix();

    placeObject.hasCharacter = true;

    placeObject.hasMatrix = true;

     swfTemp.tags.push(placeObject);

     swfTemp.tags.push(new TagShowFrame());

     swfTemp.tags.push(new TagEnd());

     var ba: ByteArray = new ByteArray();

    swfTemp.publish(ba);

     var f:FileReference = new FileReference;

    f.save(ba, fileName);

};

Source:

https://github.com/claus/as3swf/blob/master/examples/flexmania/CreateSWF.as

Take a look at this link:

http://wonderfl.net/c/6cGM