tripwire alarm

#include <Keypad.h>

#include <Keypad.h>






#define Rec 0
#define Laser 2
#define Button 3

bool detection;
short a=0;
short code[4]={'6','6','6','6'};


const byte numRows= 4;
const byte numCols= 4;

char keymap[numRows][numCols]=
          {
          {'1', '2', '3', 'A'},
          {'4', '5', '6', 'B'},
          {'7', '8', '9', 'C'},
          {'*', '0', '#', 'D'}
          };

byte rowPins[numRows] = {11,10,9,8};
byte colPins[numCols]= {7,6,5,4};

Keypad myKeypad= Keypad(makeKeymap(keymap), rowPins, colPins, numRows, numCols);

void setup() {

  pinMode(Laser, OUTPUT);
  digitalWrite(Laser, HIGH);
  delay(1000);
  Serial.begin(9600);
}

void loop() {

 short Detect = analogRead(Rec);
Serial.println(Detect);
delay(1000);

    if(Detect >1000)
        detection = true;

    if(detection==true)
        {
         tone(13,1000);
         delay(50);
         tone(13,200);
         delay(50);
         char keypressed = myKeypad.getKey();
         if (keypressed == '*')
         Getpass();
          }

     if(a==4){
         noTone(13);
         a=0;
         detection=false;
         }


}

void Getpass(){
  tone(13,2000);
  for(short i=0 ; i<4 ; i++)
            {

           char keypressed = myKeypad.waitForKey();
           Serial.println(keypressed);
              if (keypressed==code[i])
              a++;
            }
}