AS3 Centering and Resizing a background in existing code

programming flash
1

I have a code for a page I am using and I would like to add a background and have it resize with the screen like the rest of the page. I have created a movie button named “pic” with the image in it but I don’t know how to write the code and place it in the existing AS3 code file. Could someone please help. I am brand new to this so if someone could tell me how to place the code like i was in 3rd grade, that would be great. Here is the existing code.

package com.modules
{
import flash.display.;
import flash.events.;
import flash.net.;
import flash.text.;
import caurina.transitions.Tweener;
import com.utils.*;

public class About extends Sprite
{
	private var content_height:int;
	private var content_width:int;
	private var marginTop:int;
	private var marginBottom:int;
	private var content_y:int;
	
	private var _content:Content;
	private var news:News;
	private var array:Array;
	
	private var pan:Panning;
   
   public function About()
	{
		// listen for when this is added to stage
		this.addEventListener(Event.ADDED_TO_STAGE, ini);  
		// listen for when this is removed from stage
		this.addEventListener(Event.REMOVED_FROM_STAGE, remove);
    }

	private function ini(e:Event)
	{
		stage.addEventListener(Event.ADDED, onStageResize);
		stage.addEventListener(Event.RESIZE, onStageResize);
		
		content_y = int(GlobalVarContainer.vars.CONTENT_Y);
		
		_content = new Content;
		addChild(_content);
		_content.visible=false;
		
		// load xml
		if((GlobalVarContainer.vars.XML_PATH!="") && (GlobalVarContainer.vars.XML_PATH!=undefined))
		{
			var loadXml:LoadXml;
			loadXml = new LoadXml(GlobalVarContainer.vars.XML_PATH);
			loadXml.addEventListener(Event.COMPLETE, onXmlComplete);
		}
	}
	
	
	private function onXmlComplete(e:Event)
	{
		// set up content
		content_width = e.target.returnData.attribute("width");
		marginTop = e.target.returnData.attribute("marginTop");
		marginBottom = e.target.returnData.attribute("marginBottom");
		var backgroundColor = e.target.returnData.attribute("backgroundColor");
		Tweener.addTween(_content.bg, {_color:backgroundColor, time:.1, transition:"linear"});
		
		_content.bg.width = content_width;
		_content.masc.area.width = (content_width -_content.masc.x)-20;
		_content.holder.txt.width = _content.masc.area.width -10;
		
		// write text
		_content.holder.txt.mouseWheelEnabled = false;
		_content.holder.txt.styleSheet = GlobalVarContainer.vars.CSS;
		_content.holder.txt.condenseWhite = true;
		_content.holder.txt.htmlText = e.target.returnData;
		_content.holder.txt.autoSize = TextFieldAutoSize.LEFT;
		
		onStageResize();
		_content.visible=true;
		
		// create new Panning instance;
		pan = new Panning(_content.holder, _content.masc, _content.bg, 4, true); 
		pan.addEventListener(Event.ADDED, scInit); 
		addChild(pan); 
	
	}
	
	// Initialize panning
	function scInit(e:Event):void
	{
			pan.init();
	}
	
	
	// resize contents
	private function onStageResize(e:Event = null):void
	{
		resizeContent((stage.stageHeight - ((content_y + marginTop) + int(GlobalVarContainer.vars.BOTTOM_SHAPE_H)))-marginBottom);
	}
	
	private function resizeContent(height_:int):void
	{
		content_height = height_;
		_content.bg.height = content_height;
		_content.masc.area.height = (content_height -_content.masc.y)-20;
		_content.holder.mask = _content.masc;
		
		Tweener.addTween(_content, {x: Math.round(stage.stageWidth/2 - _content.width/2) , time:.5, transition:"linear"});
		_content.y=content_y+ marginTop;
	}
	
	// used to change colors. here we not use
	public function changeTheme():void
	{
	}

	
	// remove listeners, images and unload panning;
	function remove(event: Event) : void
	{
		pan.unload();
		stage.removeEventListener(Event.ADDED, onStageResize);
		stage.removeEventListener(Event.RESIZE, onStageResize);
		this.removeEventListener(Event.ADDED_TO_STAGE, ini);  
		this.removeEventListener(Event.REMOVED_FROM_STAGE, remove);
		
		trace("remove about");
	}
	
}

}