Arduino ultrasonic distance measurement

1int trigPin = 9;
2int echoPin = 10;
3int led = 7;
4
5
6void  setup() {
7  Serial.begin(9600); 
8   pinMode(led, OUTPUT);
9   pinMode(trigPin,  OUTPUT);
10  pinMode(echoPin, INPUT);
11  // put your setup code here, to run  once:
12
13}
14
15void loop() {
16  long duration, distance;
17  digitalWrite(trigPin,HIGH);
18  delayMicroseconds(1000);
19  digitalWrite(trigPin, LOW);
20  duration=pulseIn(echoPin,  HIGH);
21  distance =(duration/2)/29.1;
22  Serial.print(distance);
23  Serial.println("CM");
24  delay(10);
25 
26 if((distance<=10)) 
27  {
28    digitalWrite(led, HIGH);
29}
30   else if(distance>10)
31 {
32     digitalWrite(led, LOW);
33   }
34}

1int trigPin = 9;
2int echoPin = 10;
3int led = 7;
4
5
6void
7  setup() {
8  Serial.begin(9600); 
9   pinMode(led, OUTPUT);
10   pinMode(trigPin,
11  OUTPUT);
12  pinMode(echoPin, INPUT);
13  // put your setup code here, to run
14  once:
15
16}
17
18void loop() {
19  long duration, distance;
20  digitalWrite(trigPin,HIGH);
21
22  delayMicroseconds(1000);
23  digitalWrite(trigPin, LOW);
24  duration=pulseIn(echoPin,
25  HIGH);
26  distance =(duration/2)/29.1;
27  Serial.print(distance);
28  Serial.println("CM");
29
30  delay(10);
31 
32 if((distance<=10)) 
33  {
34    digitalWrite(led, HIGH);
35}
36
37   else if(distance>10)
38 {
39     digitalWrite(led, LOW);
40   }
41}