Make a pop up window work on a key press

Is there not a way to get this to work so as when the player is close to the game objects, and ONLY facing the object that by clicking on it with either the mouse or by pressing a key [Q] for example, that the window will pop up? And press [Q] Again to close it.

I need something like an instructional series of pop ups for game objects inside of a house which is where my FPS player will start the game. So instruction and info about objects would be good. As it is right now in it's current incarnation, the window will open no matter where you are in the game!

I've been trying to mod this script which for the most part is ideal, but needs to be tweaked so you don't fire your gun every time you want it to open and ONLY open when you are right in front of an object that has information about it.

Also would be great if this could be somehow made to access multiple info windows for many different game objects... I'm surprised there is not something like this already pre made and set up as a popular game mechanic??!!

(See Below) that I found on this most excellent question http://answers.unity3d.com/questions/8144/trying-to-pick-up-and-see-paper-pop-up-gui-window-to-examine-objects-when-click

It's perfect for what I need ONLY thing is, is that when I use my mouse pointer and then press fire on my mouse I waste ammo just oppening the pop up window.

So how can I make this where the pop up will open when my player presses [Q] key and have it close by using the [Q] key also.

also what would make this even more perfect is that if you walk away from the key the window closes automatically.

How can I do this?

EDIT

THIS IS THE SCRIPT THAT GOES ON THE GAME OBJECT TO BE CLICKED

var popupTexture : Texture2D; private var keyPopup : KeyPopup;

     if (popupTexture == null) {
         popupTexture = renderer.material.mainTexture;



     }

     keyPopup.Show(this);

}

EDIT

THIS IS THE SCRIPT THAT GOES ON THE GUI TEXTURE (Popup) I updated this with What Dave gave me and it works on a key press But how to make this so it works ONLY when my FPS player is facing the object and ONLY when close enough to pick up the object?? :

function Start() { Hide(); }

     if (!guiTexture.enabled) {
         var t = key.popupTexture;
         var rect = Rect( -t.width/2, -t.height/2, t.width, t.height );
         guiTexture.pixelInset = rect;
         guiTexture.texture = t;
         guiTexture.enabled = true;


     }

function Update() { // see if we are looking in the general direction of this thing, and within 2 meters of it var viewPos : Vector3 = Camera.main.WorldToViewportPoint (transform.position); if ((viewPos.x > .1 && viewPos.x < .9 && viewPos.z > 0) && (transform.position - Camera.main.transform.position).magnitude < 2.0) { if (Input.GetKeyDown("Action")) guiTexture.enabled = !guiTexture.enabled; } else // looking away, or too far away guiTexture.enabled = false; }