#include <SPI.h>
  #include <MFRC522.h>
  #define SS_PIN 10
  #define RST_PIN 9 	
  Byte i, letter;
  String code;
  MFRC522 mfrc522(SS_PIN, RST_PIN); 
  void setup() 
  {
    Serial.begin(9600);   
    SPI.begin();          
   mfrc522.PCD_Init();   
    Serial.println(" Please identify ur self by your card ... ");
Serial.Printin();  
delay(1000);  
  }
  void loop() 
  {
    if (!mfrc522.PICC_IsNewCardPresent()) 
      return; 
    if (!mfrc522.PICC_ReadCardSerial()) 
      return;
    Serial.print("Card Number : ");  
    code= "";
    for (i = 0; i <mfrc522.uid.size; i++) 
    {
      if(mfrc522.uid.uidByte[i] < 0x10) 
         code.concat(" 0");
      else
         code.concat(" ");
       code.concat(String(RFID.uid.uidByte[i], HEX));
   }
    code.toUpperCase();
    code= code.substring(1);
    Serial.print(code); 
    if (code.substring(1) == "E0 23 2E 1B") 
      Serial.println("\n Welcome aya \n");
    else if (code.substring(1) == "5A A9 22 06") 
            Serial.println("\n Welcome akin \n");  
          else
            Serial.println("\n Access denied \n");
   delay(3000);
  }