#define trigPin 7
#define echoPin 6
#define LEDlampRed 9
#define LEDlampYellow 10
#define LEDlampyGreen 11
#define soundbuzzer 3
int sound=5000;
void setup() {
  // put your setup code here, to run once:
Serial.begin(9600);
pinMode(trigPin,OUTPUT);
pinMode(echoPin, INPUT);
pinMode(LEDlampRed, OUTPUT);
pinMode(LEDlampYellow, OUTPUT);
pinMode(LEDlampGreen, OUTPUT);
pinMode(soundbuzzer, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
long durationindigit,distanceincm;
digitalWrite(trigPin, LOW);
delay(2000);
digitalWrite(trigPin, HIGH);
delay(10000);
digitalWrite(trigPin, LOW);
durationindigit=pulseIn(echoPin,HIGH);
distanceincm=(durationindigit/5)/29.1;

if(distanceincm<50)
{
  digitalWrite(LEDlampGreen, HIGH);
}
else
{
  digitalWrite(LEDlampGreen,LOW);
}
if(distanceincm<20)
{
  digitalWrite(LEDlampYellow, HIGH);
}
else
{
  digitalWrite(LEDlampYellow, LOW);
}
if
}