Switching relay with Ultrasonic sensor

const int trigPin = 2;
const int echoPin = 3;
const int relay = 10;
long duration;
int distance;
int safetyDistance;

void setup() {
  // put your setup code here, to run once:
pinMode(trigPin, OUTPUT); // Sets the trigPin as an Output
pinMode(echoPin, INPUT);
pinMode(relay, OUTPUT);// Sets the echoPin as an Input
Serial.begin(9600); // Starts the serial communication
}

void loop() {
  // put your main code here, to run repeatedly:


// Sets the trigPin on HIGH state for 10 micro seconds
digitalWrite(trigPin, LOW);
delayMicroseconds(2);

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;
Serial.println(distance);
delay(50);
safetyDistance = distance;
if((distance>=25))
  {
    digitalWrite(relay, LOW);
}
   else if(distance<25)
 {
     digitalWrite(relay, HIGH);
   }
}