Autodoor

#include <Servo.h>
Servo door;
const int trigPin = 9;
const int echoPin = 10;
// defines variables
long duration;
int distance;
int i;
int pos=0;
void setup() {
pinMode(trigPin, OUTPUT); // Sets the trigPin as an Output
pinMode(echoPin, INPUT); // Sets the echoPin as an Input
Serial.begin(9600); // Starts the serial communication
door.attach(3);
door.write(0);
delay(500);
}
void loop() {
// Clears the trigPin
digitalWrite(trigPin, LOW);
delayMicroseconds(2);
// Sets the trigPin on HIGH state for 10 micro seconds
digitalWrite(trigPin, HIGH);
delayMicroseconds(10);
digitalWrite(trigPin, LOW);
// Reads the echoPin, returns the sound wave travel time in microseconds
duration = pulseIn(echoPin, HIGH);
// Calculating the distance
distance= duration*0.034/2;
// Prints the distance on the Serial Monitor
Serial.print("Distance: ");
Serial.println(distance);
if(distance<=5)
{
  for(i=pos; i<120; i++)
  {
    door.write(i);
    delay(5);
    pos=i;
  }
  delay(2000);
}
else
{
  for(i=pos; i>0; i--)
  {
    door.write(i);
    delay(5);
    pos=i;
  }
  delay(2000);
}
delay(2000);
}