Code of sensor with Buzzer

#include <Ultrasonic.h>
#define  pino_trigger 8
#define pino_echo 9
Ultrasonic ultrasonic(pino_trigger, pino_echo);
void setup()
{
  Serial.begin(9600);
  Serial.println("Lendo dados do sensor...");
}
void loop()
{
  register short int pino_buzzer = 10;
  register float cmMsec = 0;
  long microsec = ultrasonic.timing();
  cmMsec = ultrasonic.convert(microsec, Ultrasonic::CM);
  Serial.println(cmMsec);
  if ((cmMsec > 0) && (cmMsec < 150))
  {
    if (cmMsec <= 150)
    {
      for (int freq = 0; freq < 20000; freq+=250) {
        tone(pino_buzzer, freq);
      }
    }else if ((cmMsec > 150) && (cmMsec < 200))
    {
        for(int freq = 0; freq < 20000; freq+=800)
        {
          tone(pino_buzzer, freq);
        }
    }
  }else
  {
    noTone(pino_buzzer);
  }
}