Code of project not working (interruptor by sound)

Hello guys
I´ve been working on this Project and the code soes not seem to work. Any ideas on why it doesn´t. i would be glad if someone checked it. plz

The site (it is in spanish, sorry): http://rogerbit.com/wprb/2016/08/interruptor-por-sonido-aplauso/

encender_con_sonido.ino (1.18 KB)

There was no reason to attach such a small amount of code.

//Más proyectos en http://www.rogerbit.com
//Suscribete en http://www.youtube.com/user/carlosvolt?sub_confirmation=1
//Grupo en Facebook https://www.facebook.com/groups/RogerBit/
int luz =13;//pin 13 arduino
int sensorSonido =2;//pin 2 donde conectaremos el módulo fc-04
int sonido =0;
int var=0;
void setup() {
  Serial.begin(19200);//Velocidad del puerto serial
  pinMode(sensorSonido,INPUT);//configura el pin 2 como entrada
  pinMode(luz, OUTPUT);// configura el pin 13 como salida
}

void loop() {
 var = digitalRead(sensorSonido);// lectura del pin 2 si se detecta un sonido fuerte como un aplauso le asigna un valor verdadero
 if (var == HIGH){//si la condición se cumple enciende el foco
 Serial.println("encendido");//imprime la leyenda encendido en terminal serial
 digitalWrite(luz, HIGH);//pone el alto el pin 13 que alimenta un módulo relay 
 sonido=sonido+1;//le suma el valor 1 a la variable sonido, si volvemos a apludir el valor será 2
 delay(80);//antirrebote
 }
if(sonido==2){//si el valor de la variable es 2 apaga el foco
 Serial.println("apagado");//implime el la leyenda apagado en el terminal serial
 digitalWrite(luz, LOW);//pone en estado LOW el pin número 13
 sonido=0;
  }
 }

What is attached to pin 2? Does that thing ASSURE that the pin is always HIGH or LOW?

What does the code ACTUALLY do? What do you expect it to do?

My crystal ball shows the LED either ON or OFF all the time. Right?

It is supposed to turn on or off by clapping.

Then you should adjust your suppositions or your code.

Oh well sorry Mr, I was posting here to get some help on the code. If you are not going to help, please don´t post

You should answer already posted questions before waiting for answers.