Light Changer Photoresistor

int photoResistor = A4;
const int BlueBoy = 3;
const int RedBoy = 11;
const int GreenBoy = 5;
const int LED1 = 9;
const int Button = 12;
int buttonRead;
int photoVal;

unsigned long timecount;
int minVal = 1000;
int maxVal = 0;
bool currentValue = false;
bool lastValue = false;


void setup() {
  // put your setup code here, to run once:
Serial.begin(9600);
pinMode (Button, INPUT);
pinMode (photoResistor, INPUT);
pinMode (BlueBoy, OUTPUT);
pinMode (RedBoy, OUTPUT);
pinMode (GreenBoy, OUTPUT);
pinMode (LED1, OUTPUT);
calibrate();
}

void calibrate() {
digitalWrite(LED1, HIGH);
delay(50);
digitalWrite(LED1, LOW);
timecount = millis();
while (millis() - timecount < 5000) {
  photoVal = analogRead(photoResistor);
  if (photoVal > maxVal) {
    maxVal = photoVal;
  }
  if (photoVal < minVal) {
    minVal = photoVal;
  }
}
}

void loop() {
  buttonRead = analogRead(Button);
  boolean current = digitalRead(Button);
  if (lastValue != current)
  {
    delay(5);
    currentValue = digitalRead(Button);
  }
  if (lastValue == LOW && currentValue == HIGH){
     calibrate();
   }
  photoVal = analogRead(photoResistor);
  Serial.println(photoVal);
  photoVal = map(photoVal, minVal, maxVal, 255, 0);
  photoVal = constrain(photoVal, 0, 255);
  analogWrite(BlueBoy, photoVal);
  analogWrite(RedBoy, photoVal);
  analogWrite(GreenBoy, photoVal);
  lastValue = currentValue;
}