Raycast from touch, return if hit a specific object.

I've been working at this code for a little bit now, I need to get it so that when the user taps the screen it sends a ray from his touch position, if this ray hits "greenbox" then it continues beyond the "if" statement. Here's what I have so far, the problem is under the "tapgreen" function

 #pragma strict
 var bestscore;
 var score : float;
 var levelchose : int;
 var levelmultiplier : int;
 var timerscript : Timer;
 var greenbox : GameObject;
 var greenboxcollide : Collider;
 var scorecounter : Transform;
 
 timerscript = gameObject.GetComponent("Timer");
 
 function Start () {
 Startgame();
 levelmultiplier = 1;
 
 
 }
 
 
 function Update () {
 
 // Do a ready, set, go function
 
 }
 
 function Startgame () {
 levelchose = Random.Range(1, 1);
 if (levelchose == 1)
 
 {
 Tapgreen();
 }
 
 Debug.Log("Didn't flip");
 
 
 }
 
 function Challengecomplete () {
 timerscript.Timerstop();
 
 score = score + timerscript.finaltime*levelmultiplier;
 levelmultiplier = levelmultiplier+1;
 Instantiate (scorecounter, Vector2(0.0, 0.0), Quaternion.identity);
 
 
 
 
 
 }
 function OnGUI()
 {
 GUI.Box(new Rect(100, 10, 50, 20), "" + score.ToString("0"));
 }
 
 function Tapgreen () {
 
 
 // Player must tap the green square.
 Debug.Log("Ready");
 yield WaitForSeconds (2);
 Debug.Log("Set");
 yield WaitForSeconds (2);
 Debug.Log("GO!");
 timerscript.Timerstart();
 Instantiate (greenbox, Vector2(Random.Range(-2.68, 2.68), Random.Range(-4.5, 4.5)), Quaternion.identity);
 
 
 for (var touch : Touch in Input.touches) {
 if (touch.phase == TouchPhase.Began) {
 // Construct a raycast from the coordinates of the touch
 var ray = Camera.main.ScreenPointToRay (touch.position);
 var hit : RaycastHit;
 if (Physics.Raycast(ray, hit)) {
 
 if (hit.collider == greenbox.collider)
 {
 // If ray collides
 Destroy (greenbox);
 Challengecomplete();
 }
 
 
         }
     }
 }
 
 
 }
 function Slider () {
 //Player must slide slider all the way to the right
 }
 
 
 
 function Gameover () {
 Debug.Log("Gameover function called");
 score = score + timerscript.timer*levelmultiplier;
 }