int led1 = 13;
int led2 = 12;
int led3 = 11;
int led4 = 10;
int pot = A0;
int button = 2;



void setup() {
  // put your setup code here, to run once:
Serial.begin(9600);
pinMode(led1, OUTPUT);
pinMode(led2, OUTPUT);
pinMode(led3, OUTPUT);
pinMode(led4, OUTPUT);
pinMode(pot, INPUT);
pinMode(button, INPUT_PULLUP);

}

void loop() {
  // put your main code here, to run repeatedly:
int potValue = analogRead(pot);
int mappPotValue = map(potValue, 0, 1023, 0, 4);

bool buttonState = digitalRead(button);

if(buttonState = LOW) {
 for(int i = 0; i<=mappPotValue; i++){
  digitalWrite(led1, HIGH);
  delay(500);
  digitalWrite(led1, LOW);
 }
}

}