Make a GUI Interact ONLY when you enter a collider (Help Please)

I am trying to custom this code so the GUI does not pop up until you hit a collider. Right now it is stuck on the screen and kind of annoying lol.

 

var pWord : String = "1234";
var usePassWord : boolean;
var myGUIText : GUIText;

private var openDoor : boolean;
private var enterZone : boolean;
private var openRot = Vector3(0,120,0);
private var defaultRot = Vector3(0,0,0);
private var doorCode : String = "1234";
private var buttonMessage : String = "Access Denied";
///=========================================================================///
function Start(){
//------------//
defaultRot = transform.eulerAngles;
//------------//
if(myGUIText) { myGUIText.gameObject.active = false; }
//------------//
openRot = new Vector3(defaultRot.x, defaultRot.y + openRot.y, defaultRot.z);
//------------//
}
///========================================================================================///
function Update (){
//------------//
if(openDoor){
transform.eulerAngles = Vector3.Slerp(transform.eulerAngles, openRot, Time.deltaTime * 2); // Open door
}
else{
transform.eulerAngles = Vector3.Slerp(transform.eulerAngles, defaultRot, Time.deltaTime * 2); // Close door
}
//------------// Not being used on a key code door
if(!usePassWord) {
if(Input.GetKeyDown("f") enterZone){
openDoor = !openDoor;
}
}
//------------//
}
///========================================================================================///
function OnTriggerEnter (other : Collider){
//------------//
if(myGUIText) { myGUIText.text = "Oops! Dead end. Keep trying!"; }
if(myGUIText) { myGUIText.gameObject.active = true; }
//------------//
if (other.gameObject.tag == "Player") {
enterZone = true;
}
//------------//
}
///========================================================================================///
function OnTriggerExit (other : Collider){
//------------//
if(myGUIText) { myGUIText.text = ""; }
if(myGUIText) { myGUIText.gameObject.active = false; }
//------------//
if (other.gameObject.tag == "Player") {
enterZone = false;
}
//------------//
}
///========================================================================================///
function OnGUI(){
//------------//
pWord = GUI.TextField (Rect (20, 100, 70, 25), pWord, 4);
//------------//
if(pWord == doorCode){
buttonMessage = "OpenDoor";
}
else{
buttonMessage = "Access Denied";
}
if(GUI.Button(Rect(95, 100, 95, 35), buttonMessage) pWord == doorCode){
openDoor = true;
}
//------------//
if(usePassWord) {
if(enterZone){
GUI.Label(new Rect(Screen.width/2 - 75, Screen.height - 100, 250, 30), "Enter Key Code Then Press 'F' to open");
}
}
else {
if(enterZone){
GUI.Label(new Rect(Screen.width/2 - 75, Screen.height - 100, 250, 30), "Press 'F' to open the door");
}
}
//------------//
}
///========================================================================================///