Adding A Lap System to Finish Line Script

Hello. I have a finish line script although I want to add a lap system, in which laps are counted in the top right corner, and when, for instance, three laps are done, the finish line works as normal. This is my current script:

 var finished:boolean = false;
 var winningPicture:Texture;
 var timer:UI.Text;
 var raceTime:float=0.0;
 
 function OnTriggerEnter()
 {
     Debug.Log("You win!");
     finished = true;
 }
 
 function OnGUI()
 {
     if (finished) //Means if finished is true?
     {
         GUI.Label   (Rect  (Screen.width/2 - 130, Screen.height/2 - 150, 696, 252), winningPicture);
         if (GUI.Button (Rect (Screen.width/2 - 150, Screen.height/2 + 50, 300, 40), "Restart Game"))
         {
             Debug.Log ("Restart button was pressed...");
             Application.LoadLevel ("Main");
         }
     }
     
 }
 
 function Update ()
 {
     if (!finished)
     {
         raceTime = raceTime+1*Time.deltaTime;
         timer.text = raceTime.ToString("f2");
     }
 }

Your help will be much appreciated. Thanks in advance. :)