Health Bar not 100% full
===

I have a health bar that, on entering the frame, it decreases slightly and isnt full. How can I fix this? The "Should be" represents what I want it to look like. The "What it currently is" represents the problem I'm having.

Should be: <img src="http://i.imgur.com/n2pY1.png">

What is currently is: <img src="http://i.imgur.com/PT7He.png">

    package  
    {
	
	import flash.display.MovieClip;
	import flash.display.Sprite;
	import flash.events.Event;
	import flash.events.TimerEvent;
	import flash.events.KeyboardEvent;
	import flash.utils.Timer;
	import flash.text.Font;
	import flash.events.MouseEvent;
	import flash.text.TextDisplayMode;
	import flash.text.TextExtent;
	import flash.text.TextField;
	import flash.text.TextFormat;
	import fl.motion.easing.Back;
	import flash.display.DisplayObject;
	import flash.geom.Point;
	import flash.ui.Mouse;
	import flash.events.TimerEvent;

	
	public class healthBar extends MovieClip 
	{
		
		public var maxHP:int = 670;
		public var currentHP:int = maxHP;
		public var percentHP:Number = currentHP / maxHP;
		
		public function healthBar() 
		{
                updateHealthBar();
		}
		public function updateHealthBar()
		{
			percentHP = currentHP / maxHP;
			scaleX = percentHP;
		}

	}
	
    }
