Problem with digitalread

Hi, I need help.

I can not do that, when I press a button, the red light turns on and the green light turns off.
And when the button is not pressed, the green light turns on and the red light turns off.

This is my program:

const byte botonEST = 0;
const byte pinGREEN   = 2;
const byte pinRED    = 3;
const byte pinBTN     = 4;
const byte pinSENSOR  = 5;
const byte pinALARMA  = 7;

void setup() {
  pinMode(pinGREEN,  OUTPUT);
  pinMode(pinRED,   OUTPUT);
  pinMode(pinALARMA, OUTPUT);
  pinMode(pinBTN,    INPUT);
  pinMode(pinSENSOR, INPUT); 

void loop() {
   const byte botonEST = digitalRead(pinBTN);
  if (botonEST == 0){
    digitalWrite(pinRED, LOW);
    digitalWrite(pinGREEN, HIGH);
    Serial.println("- Alarma: ON.");
  } else {
    digitalWrite(pinRED, HIGH);
    digitalWrite(pinGREEN, LOW);
    Serial.println("- Alarma: OFF.");

You can help me? Thanks.

u dont want this--

const byte botonEST = digitalRead(pinBTN);

just do this--

if(digitalRead(pinBtn)) { }

else { }

True - but makes no difference to the problem

@op - what do you expect? what do you get?

PS - @ both just what does const mean?