Problem vid GuiTexture

Hello! I have a problem with my paper popup script. When I walk up to a paper, a text pops up "[E] Read note", when pressing "E" a GuiTexture pops up, and when you left click it closes.

The problem I have is when there's multiple notes around the map. It seems that I can only pick up one note, because when I try to pick up a second one, it just disappears.

Does anyone no what the problem is?

//Paper.js

 private var buttonInRange = false;
 var note : AudioClip;
 public var popupObject : GameObject;
 public var guiSkin : GUISkin;
 
 private var popupScript : PaperPopup;
 
 function Start ()
 {
     popupScript = popupObject.GetComponent(PaperPopup);
 }
  
  
 function OnTriggerStay (c : Collider)
 {
     buttonInRange = true;
 }
 function OnTriggerExit (c : Collider)
 {
     buttonInRange = false;
 }
 function OnGUI()
 {
     if(buttonInRange == true)
     {
         GUI.skin = guiSkin;
         GUI.Label (Rect (Screen.width/2-50, Screen.height/2-55, 120, 50),"[E] Read note");
     }
 }
 
 function Update ()
 {
     print(gameObject+" buttonInRange = "+buttonInRange);
     
     if(buttonInRange == true)
     {
         if (Input.GetKeyDown ("e"))
         {
             print(popupScript+" is showing");
                AudioSource.PlayClipAtPoint(note, transform.position);
                popupScript.Show();
                Destroy (gameObject);
         }
     }
 }

//PaperPopup.js

 public var paperObject : Texture2D;
 
 function Start()
 {
     Hide();
 }
 
 function Hide()
 {
     guiTexture.enabled = false;
 }
 
 function Show()
 {
     if (!guiTexture.enabled)
     {
         var rect = Rect( -paperObject.width/3, -paperObject.height/2, paperObject.width, paperObject.height );
         guiTexture.pixelInset = rect;
         guiTexture.texture = paperObject;
         guiTexture.enabled = true;
     }   
 }
 
 function OnMouseDown ()
 {
     Hide();
 }