RepeatButton with new UI Button in Javascript

So before Unity 4.6 I used a GUI button that when held down a timer would count up.

Here is My old code

 var counter: int = 0; 
 var Timer = 0.0;
 var gameText: GUIText;
 var btnStyle:GUIStyle;
 var backGround:GUIStyle;
  
 function Start(){ 
     gameText = gameObject.GetComponent(GUIText); 
 }
 function OnGUI () {
 GUI.Box (Rect (100,100,200,300), "Hold IT", backGround); 
     if (GUI.RepeatButton(new Rect(50,50,100,110),"", btnStyle)) {
     counter++;
     Timer += Time.deltaTime;
     var hours : int =  Timer / 3600;
     var minutes : int = Timer / 60;
     var seconds : int = Timer % 60;
     var fraction : int = (Timer * 100) % 100;
     gameText.text = String.Format ("{0:00}:{1:00}:{2:00}:{3:00}", hours, minutes, seconds, fraction);  
     }
   }  

So i thought id give the new UI button a try. I put this code on the button so when you hold it down it would start a timer. But I dont know how I can use the RepeatButton function with the new UI Button.

 #pragma strict
 var counter: int = 0; 
 var Timer = 0.0;
 var gameText:UI.Text; 
 
 function Start(){
 gameText = GetComponent(UI.Text);
 }
 function Update () {
 counter++;
     Timer += Time.deltaTime;
     var hours : int =  Timer / 3600;
     var minutes : int = Timer / 60;
     var seconds : int = Timer % 60;
     var fraction : int = (Timer * 100) % 100;
     gameText.text = String.Format ("{0:00}:{1:00}:{2:00}:{3:00}", hours, minutes, seconds, fraction); 
 }

How will the RepeatButton work ?? Do I still have to use function OnGUI() for it to work?