int distance=0;
int red =4;
int blue =5;
int green =6;
long readUltrasonicDistance(int triggerPin,int echoPin)
{
  pinMode(triggerPin, OUTPUT);
  digitalWrite(triggerPin,LOW);
  delayMicroseconds(2);
  digitalWrite(triggerPin,HIGH);
  delayMicroseconds(10);
  digitalWrite(triggerPin,LOW);
  pinMode(echoPin,INPUT);
  return pulseIn(echoPin,HIGH);
}
void setup()
{
  pinMode(4, OUTPUT);
  pinMode(5, OUTPUT);
  pinMode(6, OUTPUT);
}
void loop()
{
  distance=0.01723*readUltrasonicDistance(10,11);
  if(distance>=200)
  {
    digitalWrite(red,HIGH);
    digitalWrite(blue,LOW);
    digitalWrite(green,LOW);
    delay(2000);
  }
  if(distance>100 && distance<200)
  {
    digitalWrite(red,LOW);
    digitalWrite(blue,HIGH);
    digitalWrite(green,LOW);
    delay(2000);
  }
  if(distance<=100)
  { digitalWrite(red,LOW);
    digitalWrite(blue,LOW);
    digitalWrite(green,HIGH);
    delay(2000);
}
}