int trig = 3;
int echopin= 2;
int time;
int distance;
int buzzpin = 9;

void setup() {
  // put your setup code here, to run once:
  pinMode(trig, OUTPUT);
  pinMode(echopin, INPUT);
  pinMode(buzzpin, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  digitalWrite(trig, LOW);
  digitalWrite(trig, HIGH);
  time = pulseIn(echopin, HIGH);
  distance = time*0.0172;
  if (distance >= 30)
  {
    digitalWrite(13, HIGH);
    digitalWrite(11, LOW);
  }
  else
  {
    digitalWrite(13, LOW);
    digitalWrite(11, HIGH);
    tone(buzzpin, 1100, 300);
    delay(100);
    tone(buzzpin, 700, 100);
    delay(100);
  }
}