Local Variables

Hello, all. This should be simple and quick. I have a prefab. This prefab has a script that is a timer. The script has a variable that the time of the timer is stored in. The problem is, I will have more than one instance of this prefab, and eery time I instantiate a new one, it picks up where the timer from the first one left off. Is there any way I can make it so that the other duplicates do NOT use the same variables, but keep separate copies of the same variable for themselves? thanks - YA

Here is the code.

 var yellowTex : GUITexture;
 private var xpos : float;
 private var ypos : float;
 private var scale : float = -0.8;
 private var scaledelta : float;
 private var position = Vector3(-0.002426388,0.205147,1);
 private var xdelta : float;
 private var ydelta : float;
 private var created : boolean;
 private var yellow : GUITexture;
 var TravelTime : float = 2;
 var TimeStart : float = 0.0;
 //Beginning coordinates are (-0.002426388,0.205147,1);
 //Ending coordinates are (-0.02,0.02,1);
 function Update () {
     if(Input.GetButtonDown("Vertical")){
     yellow = Instantiate(yellowTex, position, Quaternion.identity);
     created = true;
     yellow.transform.localScale = Vector3(-0.8, -0.8, 1);
     }
     if(yellow){
     //calculating x and y positions
     xdelta = ((-0.02 - -0.002426388)/TravelTime)*TimeStart;
     ydelta = ((0.02 - 0.205147)/TravelTime)*TimeStart;
     ypos = 0.205147 + ydelta;
     xpos = -0.002426388 + xdelta;
     //updating position
     yellow.transform.position = Vector3(xpos,ypos,1);
     //calculating scale values
     scaledelta = ((0 - -0.8)/TravelTime)*TimeStart;
     scale = -0.8 + scaledelta;
     //updating scale
     yellow.transform.localScale = Vector3(scale,scale,1);
     }
     if(created == true){
     CountUpwards();
     }
 }
 //The timer function
 function CountUpwards(){
     TimeStart += Time.deltaTime;
     }