Arduino Program

Hello!
I made four diffrent programs for a project I made. But now that I tried to combine them something isn't working.
Please help.

#include "SPI.h"  
#include "MFRC522.h"
#include <Password.h>
#include <Keypad.h> 
#include <LiquidCrystal.h>

#define SS_PIN 10  
#define RST_PIN 9 

int vklop;

MFRC522 rfid(SS_PIN, RST_PIN);  

MFRC522::MIFARE_Key key; 

LiquidCrystal lcd(A5, A4, 8, 7, 1, 0);  

Password password = Password( "1234" ); 

const byte ROWS = 4; 
const byte COLS = 4; 

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

byte rowPins[ROWS] = { 3,4,5,6 }; 
byte colPins[COLS] = { A0,A1,A2,A3 };

Keypad keypad = Keypad( makeKeymap(keys), rowPins, colPins, ROWS, COLS ); 

int state = 0; 
int flag = 0;  

void setup() {
  lcd.begin(16, 2); 
  lcd.clear(); 
  SPI.begin();
  rfid.PCD_Init();  
  pinMode(2, OUTPUT); 
  keypad.addEventListener(keypadEvent);
  
}

void loop() {
  keypad.getKey();


  
  if (!rfid.PICC_IsNewCardPresent() || !rfid.PICC_ReadCardSerial()) 

  MFRC522::PICC_Type piccType = rfid.PICC_GetType(rfid.uid.sak); 
  if (piccType != MFRC522::PICC_TYPE_MIFARE_MINI && 
      piccType != MFRC522::PICC_TYPE_MIFARE_1K &&
      piccType != MFRC522::PICC_TYPE_MIFARE_4K) {
    return;
  }
  String strID = "";
  for (byte i = 0; i < 4; i++) {
    strID +=
      (rfid.uid.uidByte[i] < 0x10 ? "0" : "") +
      String(rfid.uid.uidByte[i], HEX) +
      (i != 3 ? ":" : "");
  }
 
  strID.toUpperCase();
  delay(1000);

  if (strID.indexOf("02:72:B1:89") >= 0) { 


   if(digitalRead(2) == HIGH) { 
    digitalWrite(2, LOW); 
    lcd.clear(); 
    delay(10);
    lcd.print("ZAPRTO"); 
    delay(1000);
    }
    else if(digitalRead(2) == LOW) { 
      digitalWrite(2, HIGH); 
      lcd.clear(); 
      delay(10);
      lcd.print("ODPRTO"); 
      delay(1000);
    
    }
    
   
    
    }
   
  else {
  }



if(Serial.available() > 0){ 
 state = Serial.read(); 
 }

 if (state == '0') {  
 digitalWrite(2, LOW); 
    
 if(flag == 0){ 
    lcd.clear(); 
    delay(10);
    lcd.print("ZAPRTO"); 
 flag = 1; 
 }
 }

 else if (state == '1') { 
 digitalWrite(2, HIGH); 
 
 if(flag == 0){ 
    lcd.clear();
    delay(10);
    lcd.print("ODPRTO"); 
 flag = 1; 
 }
 } 
}



void keypadEvent(KeypadEvent eKey){ 
  switch (keypad.getState()){
  case PRESSED:
  
  delay(10);

  
  switch (eKey){
    case '#': checkPassword(); delay(1); break;
    
    case '*': password.reset(); delay(1); break; 

    case 'A': digitalWrite(2, LOW);
    lcd.clear();
    delay(10);
    lcd.print("ZAPRTO");
    password.reset();
    break;
    
     default: password.append(eKey); delay(1);
}
}
}
void checkPassword(){
  
if (password.evaluate()){
    lcd.clear();
    delay(10);
    lcd.print("ODPRTO");
    delay(10);
    digitalWrite(2,HIGH);   
}
else{
delay(10);
}
}

Maybe start by looking here: https://arduino-info.wikispaces.com/CombiningArduinoSketches

something isn't working.

Doesn't give us much to go on, does it ?

In addition, because you did not read this before posting a programming question and follow the advice to use code tags when posting code here some of it has been turned into italics making it difficult to follow and copy/paste into an editor.

Post your combined code, a description of what it should do, what it actually does (if anything) and the full error messages (if) that you get when compiling it.

Thread locked: Need help! - #8 by Coding_Badly - Programming Questions - Arduino Forum