NOTE: pressing two button (simultaneously) = LED light ON

#define ledPin 12
#define buttonPin 4
#define buttonPin2 5

boolean ledState = LOW;
boolean prevBtnState = LOW;
boolean prevBtnState2 = LOW;

void setup() {
  pinMode( ledPin, OUTPUT );
  pinMode( buttonPin, INPUT );
  pinMode( buttonPin2, INPUT );
  digitalWrite ( ledPin, LOW );
}

void loop(){

  boolean btnState2 = digitalRead( buttonPin2 );

  if (btnState2 == HIGH) {    
    digitalWrite( ledPin, HIGH);
    delay( 20 );
  }
  
}

/*
void loopOld2(){
  boolean btnState = digitalRead( buttonPin );
  boolean btnState2 = digitalRead( buttonPin2 );

  if ( btnState == HIGH && btnState2 == HIGH) {
    ledState = HIGH;
    
    digitalWrite( ledPin, ledState );
    delay( 20 );
  }
  
}*/

/*void loopOld() {
  boolean btnState = digitalRead( buttonPin );
  boolean btnState2 = digitalRead( buttonPin2 );

  if ( btnState == HIGH && prevBtnState == LOW && btnState2 == HIGH && prevBtnState2 == LOW) {
    ledState = ! ledState;
    delay( 20 );
  }

  

  digitalWrite( ledPin, ledState );

  prevBtnState = btnState;
  prevBtnState = btnState2;
}*/