Ultrasonic distance detector

1#define trigPin 7
2#define echoPin 6
3#define led 13
4#define led2  12
5#define led3 11
6#define led4 10
7#define led5 9
8#define led6 8
9#define  buzzer 3
10
11int sound = 250;
12
13
14void setup() {
15  Serial.begin (9600);
16  pinMode(trigPin, OUTPUT);
17  pinMode(echoPin, INPUT);
18  pinMode(led, OUTPUT);
19  pinMode(led2, OUTPUT);
20  pinMode(led3, OUTPUT);
21  pinMode(led4, OUTPUT);
22  pinMode(led5, OUTPUT);
23  pinMode(led6, OUTPUT);
24  pinMode(buzzer, OUTPUT);
25  
26}
27
28void loop() {
29  long duration, distance;
30  digitalWrite(trigPin,  LOW); 
31  delayMicroseconds(2);
32  digitalWrite(trigPin, HIGH);
33  delayMicroseconds(10);
34  digitalWrite(trigPin, LOW);
35  duration = pulseIn(echoPin, HIGH);
36  distance  = (duration/2) / 29.1;
37 
38
39  if (distance <= 30) {
40    digitalWrite(led,  HIGH);
41    sound = 250;
42}
43  else {
44    digitalWrite(led,LOW);
45  }
46  if (distance < 25) {
47      digitalWrite(led2, HIGH);
48      sound = 260;
49}
50  else {
51      digitalWrite(led2, LOW);
52  }
53  if (distance < 20) {
54      digitalWrite(led3, HIGH);
55      sound = 270;
56} 
57  else {
58    digitalWrite(led3,  LOW);
59  }
60  if (distance < 15) {
61    digitalWrite(led4, HIGH);
62    sound  = 280;
63}
64  else {
65    digitalWrite(led4,LOW);
66  }
67  if (distance  < 10) {
68    digitalWrite(led5, HIGH);
69    sound = 290;
70}
71  else {
72    digitalWrite(led5,LOW);
73  }
74  if (distance < 5) {
75    digitalWrite(led6,  HIGH);
76    sound = 300;
77}
78  else {
79    digitalWrite(led6,LOW);
80  }
81  
82  if (distance > 30 || distance <= 0){
83    Serial.println("Out of range");
84    noTone(buzzer);
85  }
86  else {
87    Serial.print(distance);
88    Serial.println("  cm");
89    tone(buzzer, sound);
90   
91  }
92  delay(500);
93}
94