Triggering a door to open via password

I'm a beginner in Unity, creating a game for my development project. In my game, I want the character to approach a door and be prompted to input a password with only three attempts to open the door to complete the level.

I created a box in the shape of a door, then created an empty GameObject at the edge of the box (where a door hinge would be). I then made the box a child of the empty GameObject making a door that rotates from the position of the empty GameObject. I applied the following script to the door as well as a box collider that is triggered.

 // Smothly open a door
 var smooth = 2.0;
 var DoorOpenAngle = 90.0;
 private var open : boolean;
 private var enter : boolean;
 
 private var defaultRot : Vector3;
 private var openRot : Vector3;
 
 function Start(){
 defaultRot = transform.eulerAngles;
 openRot = new Vector3 (defaultRot.x, defaultRot.y + DoorOpenAngle, defaultRot.z);
 }
 
 //Main function
 function Update (){
 if(open){
 //Open door
 transform.eulerAngles = Vector3.Slerp(transform.eulerAngles, openRot, Time.deltaTime * smooth);
 }else{
 //Close door
 transform.eulerAngles = Vector3.Slerp(transform.eulerAngles, defaultRot, Time.deltaTime * smooth);
 }
 
 if(Input.GetKeyDown("d") && enter){
 open = !open;
 }
 }
 
 function OnGUI(){
 if(enter){
 GUI.Label(new Rect(Screen.width/2 - 75, Screen.height - 100, 150, 30), "Press 'D' to open the door");
 }
 }
 
 //Activate the Main function when player is near the door
 function OnTriggerEnter (other : Collider){
 if (other.gameObject.name == "Shanice") {
 enter = true;
 }
 }
 
 //Deactivate the Main function when player is go away from door
 function OnTriggerExit (other : Collider){
 if (other.gameObject.name == "Shanice") {
 enter = false;
 }
 }

This opens the door when the user presses 'd' but how do I modify this code to apply a password. I'm assuming I also need to and GUI Text?