const int ProxSensor=2; 
const int trigPin = 17;
const int echoPin = 16;
	// defines variables
long duration;
int distance;

void setup() 
{ 
   pinMode(18, OUTPUT);
pinMode(13, OUTPUT); 
pinMode(ProxSensor, INPUT); 
pinMode(trigPin, OUTPUT); 	// Sets the trigPin as an Output
pinMode(echoPin, INPUT); 	// Sets the echoPin as an Input
Serial.begin(9600); 		// Starts the serial communication
} 
void loop() 
{ 


digitalWrite(trigPin, LOW);
delayMicroseconds(2);
	// Sets the trigPin on HIGH state for 10 micro seconds
digitalWrite(trigPin, HIGH);
delayMicroseconds(10);
digitalWrite(trigPin, LOW);

	// Reads the echoPin, returns the sound wave travel time in microsec.
duration = pulseIn(echoPin, HIGH);
	// Calculating the distance
distance= (duration*0.034)/2;
	// Prints the distance on the Serial Monitor
Serial.print("Distance: ");
Serial.print(distance);
Serial.println("cm");
if(distance > 300){
  //tone(5,262,250);
  digitalWrite(18,HIGH);
}

delay(500);  //500 m.sec = 0.5 sec

if(digitalRead(ProxSensor)==HIGH) 
		{ 
		digitalWrite(13, HIGH);
		} 
else 
		{ 
		digitalWrite(13, LOW);
		} 
	delay(100);

}