My GUITexture shrinks on both sides

Hi i want my GUITexture to shrink from the left to the right with my script. But as it shrinks to the right the right side expands to the right, allthough a small ammount its enough to be noticeable.

http://gyazo.com/4dd235c4e8ff71c4f7c6c6710f381aec

http://gyazo.com/4b29e490c2bf57f06f756c4641bde8e3

Why doesnt it just reduce from the left to the right, instead of what you can see in the two pictures?

CODE if it may help.

 #pragma strict
 
 var BatteryLife : GUITexture;
 private var fl : Flashlight;
 var width : float = -116;
 
 function Start ()
 {
     fl = GameObject.Find("Flashlightt").GetComponent(Flashlight);
     BatteryLife.guiTexture.pixelInset = Rect (505.5, 221, -116, 35);
     BatteryLife.guiTexture.enabled = false;
 }
 
 function Update ()
 {
     if(Input.GetKeyDown("n"))
     {
         if(BatteryLife.guiTexture.enabled == false)
         {
             BatteryLife.guiTexture.enabled = true;
         }
         else
         {
             BatteryLife.guiTexture.enabled = false;
         }
     }
 
     BatteryDrain();
 }
 
 function BatteryDrain ()
 {
     BatteryLife.guiTexture.pixelInset.width = (fl.batteryLife * width) / 0.6;
 }