code:

// C++ code
// include the library code:
#include 

// initialize the library with the numbers of the interface pins
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);
int ultrasonic = 0;

long readUltrasonicDistance(int triggerPin, int echoPin)
{
  pinMode(triggerPin, OUTPUT);  // Clear the trigger
  digitalWrite(triggerPin, LOW);
  delayMicroseconds(2);
  // Sets the trigger pin to HIGH state for 10 microseconds
  digitalWrite(triggerPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(triggerPin, LOW);
  pinMode(echoPin, INPUT);
  // Reads the echo pin, and returns the sound wave travel time in microseconds
  return pulseIn(echoPin, HIGH);
}

void setup()
{
 lcd.begin(16, 2);

}

void loop()
{
  ultrasonic = 0.01723 * readUltrasonicDistance(A0, A1);
   lcd.setCursor(0, 1);
  // print the number of seconds since reset:
  lcd.print(ultrasonic);
  delayMicroseconds(100);
}

by mohamed hashir