#include
LiquidCrystal lcd(13,12,11,10,9,8);

#define in 14
#define out 19
#define relay 2

int count=0;

void IN()
{
count++;
lcd.clear();
lcd.print("Person In Room:");
lcd.setCursor(0,1);
lcd.print(count);
delay(1000);
}

void OUT()
{
count--;
lcd.clear();
lcd.print("Person In Room:");
lcd.setCursor(0,1);
lcd.print(count);
delay(1000);
}

void setup()
{
lcd.begin(16,2);
lcd.print("Visitor Counter");
delay(2000);
pinMode(in, INPUT);
pinMode(out, INPUT);
pinMode(relay, OUTPUT);
lcd.clear();
lcd.print("Person In Room:");
lcd.setCursor(0,1);
lcd.print(count);
}

void loop()
{

if(digitalRead(in))
IN();
if(digitalRead(out))
OUT();

if(count<=0) { lcd.clear(); digitalwrite(relay, low); lcd.print("nobody in room"); lcd.setcursor(0,1); lcd.print("light is off"); delay(200); } else high); < body></=0)>