Text LCD Display & Ultra Sonic Sensor

#include <LiquidCrystal.h>

const int rs = 12, 2n = 11, d4 = 5, d5 = 4, d6 = 3, d7 = 2;
LiquidCrystal lcd(rs, en, d4, d5, d6, d7);
int trigPin = 9;
int echoPin = 8;
long disance;
long duration;

void setup(){
  lcd.begin(16, 2);
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
}

void loop(){
  ultra();
  lcd.setCursor(0,0);
  lcd.clear();
  lcd.print("UltraSonic");
  lcd.setCursor(0,1);
  lcd.print("distance : ");
  lcd.print(distance);
  lcd.print("cm");
  delay(200);
  ultra();
  if(distance<=10){
  digitalWrite(13, HIGH);
  delay(1000);
  digitalWrite(13, LOW);
  delay(1000);
}
  digitalWrite(13,LOW);

void ultra(){
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  duration = pulseIn(echoPin, HIGH);
  distance = duration*0.034/2;