Smart parking system with arduino and IR sensors

try this:

#include <Servo.h>
#include<LiquidCrystal.h>
LiquidCrystal lcd(12, 11, 5, 4, 3, 2); //connected to RS,EN,D4,D5,D6,D7 of LCD display respectively
Servo myservo;  // create servo object to control a servo

#define ServoM    7        //Connected to the servo motor.
#define Exit      9         //Pin connected to the EXIT sensor.
#define In        8         //Pin connected to the IN sensor.
#define BarLow    90      //Low position of the barrier.
#define BarUp     177        //Up position of the barrier.
#define CAPACITY  7         //Capacity of the parking lot.

int  Available = 7;                   // Number of places available.

//================================================================
void setup() {
  myservo.attach(ServoM);          // attaches the servo.
  lcd.begin(16, 2);
  pinMode(Exit, INPUT);           // set "EXIT" sensor pin to input
  pinMode(In, INPUT);             // set "IN" sensor pin to input
  myservo.write(BarLow);          //Barrier in the low position
  delay(1000);
}

//================================================================
void loop() {
  checkForCars();
  if (Available == 1) { //If only one place is available.
    lcd.clear();       //Clear the LCD screen.
    lcd.setCursor(1, 0);
    lcd.print("disponible");//Display the text"Space left for.
    lcd.setCursor(0, 1);
    lcd.print(Available);       //Display the no. of spaces left for cars.
    lcd.print(" places");
    delay(1000);
  }
  else if (Available > 1) {
    lcd.clear();
    lcd.setCursor(1, 0);
    lcd.print("disponible");
    lcd.setCursor(0, 1);
    lcd.print(Available);
    lcd.print(" places");
    delay(1000);
  }
  else if (Available == 0) {
    lcd.clear();
    lcd.setCursor(1, 0);
    lcd.print("Désolé!");
    lcd.setCursor(0, 1);
    lcd.print("Pas d'espace!");
    delay(1000);
  }
}
void checkForCars() {
  if (digitalRead(In)) {   //If the IN sensor detects a car at the entrance.
    if (Available != 0) {   //Checking if there is place in parking lot('!=' means 'not equal to').
      Available--;          //Deduct a place from the lot in the memory.
      myservo.write(BarUp); //Lift the barrier up.
      delay(3000);
      myservo.write(BarLow);//Lower the barrier.
    }
  }
  if (digitalRead(Exit))    //If the EXIT sensor detects a car the exit.=
  {
    if (Available != CAPACITY) {
      Available++;
      myservo.write(BarUp);
      delay(3000);
      myservo.write(BarLow);
    }
  }
}