two ultrasonic sensor code

#define trigPin1 6
#define echoPin1 7

#define trigPin2 8
#define echoPin2 9

int hit1 = 0, hit2 = 0;
int numEntries = 0, numExits = 0;


// include the library code:
#include <LiquidCrystal.h>

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

void setup() {
  Serial.begin(9600);
  // set up the LCD's number of columns and rows:
  lcd.begin(16, 2);
  //Print a message to the LCD.
  lcd.print("Entity Count:");

  //sensors
  pinMode(trigPin1, OUTPUT);
  pinMode(echoPin1, INPUT);
  pinMode(trigPin2, OUTPUT);
  pinMode(echoPin2, INPUT);
  
}

void loop() {
  // set the cursor to column 0, line 1
  lcd.setCursor(0, 1);


  //check sensor1
  int duration, distance;
  digitalWrite(trigPin1, LOW);
  delayMicroseconds (2);
  digitalWrite (trigPin1, HIGH);
  delayMicroseconds (5);
  digitalWrite (trigPin1, LOW);
  duration = pulseIn (echoPin1, HIGH);
  distance = (duration/2) / 29.1;
  
  if(distance < 15){
    Serial.println("Entering...");
    hit1 = 1;
  }

  //check sensor2
  int duration2, distance2;
  digitalWrite(trigPin2, LOW);
  delayMicroseconds (2);
  digitalWrite (trigPin2, HIGH);
  delayMicroseconds (5);
  digitalWrite (trigPin2, LOW);
  
  duration2 = pulseIn (echoPin2, HIGH);
  distance2 = (duration2 / 2) / 29.1;
  
  if(distance2 < 15){
    Serial.println("Exitting...");
    hit2 = 1;
  }

  //entry was triggered, scan exit until exit is hit
  while(hit1 == 1 && hit2 == 0){
    //check sensor2
    int dur, dist;
    digitalWrite(trigPin2, LOW);
    delayMicroseconds (2);
    digitalWrite (trigPin2, HIGH);
    delayMicroseconds (5);
    digitalWrite (trigPin2, LOW);
    
    dur = pulseIn (echoPin2, HIGH);
    dist = (dur / 2) / 29.1;
    
    if(dist < 15){
      //reset the two values
      hit1 = 0;
      hit2 = 0;
      numEntries++;
      Serial.println("\tENTERED");
      delay(250);
      break;
    }
  }
  

  //exit was triggered, scan entry until entry is hit
  while(hit1 == 0 && hit2 == 1){
    //check sensor2
    int dur, dist;
    digitalWrite(trigPin1, LOW);
    delayMicroseconds (2);
    digitalWrite (trigPin1, HIGH);
    delayMicroseconds (5);
    digitalWrite (trigPin1, LOW);
    
    dur = pulseIn (echoPin1, HIGH);
    dist = (dur / 2) / 29.1;
    
    if(dist < 15){
      //reset the two values
      hit1 = 0;
      hit2 = 0;
      numExits++;
      Serial.println("\tEXITED");
      delay(250);
      break;
    }
  }

  // print the number of seconds since reset:
  lcd.print(numEntries - numExits);

  delay(500);
}