int pinSW  =  8;
int pinBuz = 11;
int pinCds =  0;

void
setup()
{
  pinMode(pinSW,  INPUT);
  pinMode(pinBuz, OUTPUT);
}

void
loop()
{
    int  sw, cds;

    sw = digitalRead(pinSW);
    cds = analogRead(pinCds);
    if (sw == HIGH) {
        digitalWrite(pinBuz, HIGH);
        delayMicroseconds(cds);
        digitalWrite(pinBuz, LOW);
        delayMicroseconds(cds);
    }
    else {
      digitalWrite(pinBuz, LOW);
    }
}