Touchless Disinfectant Sprayer

#define echoPin A2 // attach pin D2 Arduino to pin Echo of HC-SR04
#define trigPin A1 //attach pin D3 Arduino to pin Trig of HC-SR04
int buzzer =3;
int motor =6;
int potPin = A3;

// defines variables
long duration; // variable for the duration of sound wave travel
int distance; // variable for the distance measurement
int potVal;
int once = 0;
void setup() {
  pinMode(buzzer,OUTPUT);
  pinMode(motor,OUTPUT);

  pinMode(trigPin, OUTPUT); // Sets the trigPin as an OUTPUT
  pinMode(echoPin, INPUT); // Sets the echoPin as an INPUT
  Serial.begin(9600); // // Serial Communication is starting with 9600 of baudrate speed
  Serial.println("Ultrasonic Sensor HC-SR04 Test"); // print some text in Serial Monitor
  Serial.println("with Arduino Pro Mini");
  digitalWrite(buzzer,HIGH);
  delay(500);
  digitalWrite(buzzer,LOW);
  delay(500);

}

void loop() {
  // Clears the trigPin condition
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  // Sets the trigPin HIGH (ACTIVE) for 10 microseconds
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  // Reads the echoPin, returns the sound wave travel time in microseconds
  duration = pulseIn(echoPin, HIGH);
  // Calculating the distance
  distance = duration * 0.34 / 2; // Speed of sound wave divided by 2 (go and back)
  // Displays the distance on the Serial Monitor
  
  potVal = analogRead(potPin)/2;
  Serial.print("potVal: ");
  Serial.print(potVal);
  
  
  Serial.print(" once: ");
  Serial.print(once);
  
  Serial.print("  Distance: ");
  Serial.print(distance);
  Serial.println(" mm");
  
  delay(100);
  if (distance <70)
  {
    digitalWrite(buzzer,HIGH);
    //delay(1);
    if (once == 0)
    {
      
       
    digitalWrite(motor, HIGH);
    delay(potVal);
    digitalWrite(motor,LOW);
    
    once =1;
    }
    delay(100);
    digitalWrite(buzzer,LOW);
    
 }
 else
 {
  once=0;
  
  }
 
}