Specific Items Being Clicked

Relative newbie, and I have a few questions, and one that's on the top of my head involves mouse inputs. I have a really simple scene, testing out a shuffle bag script I found on the forums here. In the scene there's a flat plane, a cube, and a sphere. I have this script attached to the cube…

 #pragma strict
 #pragma implicit
 
 static class ShuffleBag{ 
 
     var data = new Array(); 
     var cursor=-1;
     
     function add(item, num : int) {
         var i = num || 1;
         while(i--)
         {
             data.push(item);    
         }
         cursor = data.length -1;
     } 
     
     function next() { 
         var grab; 
         var temp;
         if(cursor<1) { 
             cursor = data.length-1; 
             return data[0]; 
         }
         grab = Random.Range(0, cursor+1);
         temp = data[grab];
         data[grab]= data[cursor];
         data[cursor] = temp;
         cursor--;
         return temp;
     }
     
 }
      
 function Start()
 {
 
 }
 
 var display : GUIText;
 var displaylife = 1.0;
 
 function Update()
 {
     
      if(Input.GetMouseButtonDown(0)){
         var hit : RaycastHit;
         var ray = Camera.main.ScreenPointToRay(Input.mousePosition);
         if (Physics.Raycast(ray, hit)){
             //startTime = Time.time;
             //point = hit.point;
             //object = hit.transform.gameObject;
             
             ShuffleBag.add(0,1);
             ShuffleBag.add(1,3);
             print(ShuffleBag.next());
             
             if(ShuffleBag.next() == 1){
                 var clonedisplay = Instantiate(display);
                 display.text = 'Hit!';
                 Destroy(clonedisplay, displaylife);
             }
             
             else if(ShuffleBag.next() == 0){
                 var clondedisplay = Instantiate(display);
                 display.text = 'Miss!';
                 Destroy(clonedisplay, displaylife);
             }
         }
     }
     else if (Input.GetMouseButtonUp(0)){
         //duration = Time.time - startTime;
         Destroy(clonedisplay, displaylife);
     }
     
     Destroy(clonedisplay, displaylife);
 
 }

With a floating camera and when I point my camera at the cube, sphere, or plane, I get the same results from the if statements nested in Update(). How do I make it so it only the cube creates the GUItext display?

I know it's bad manner to ask two questions in one, but additionally, I'm curious why when the prefab for GUIText comes up, eventually the Hit! display won't be destroyed / removed and gets stuck on screen. Any idea how to better employ this display?

Thanks in advance!