Please Help!!

Using Arduino Programming Questions
54

i changed the interval to 500 and it now seems to be on for longer...

byte triggerright=2;  // declaring the pins which will be in use
byte echoright = 3;
float distance;
const int buzzer = 10;
byte red=7;
byte yellow=8;
byte green=4;
float distanceread;
long previousMillis=0;
int buzzerState = LOW;
long interval = 500;
void setup (){
  pinMode(buzzer, OUTPUT);
  pinMode (triggerright, OUTPUT);
  pinMode (echoright, INPUT);
  pinMode(red, OUTPUT);
  pinMode(yellow, OUTPUT);
  pinMode(green, OUTPUT);
  Serial.begin (9600);    // set up the baud rate for serial printing 
}

void loop (){

  distanceread = getDistance ();



  if(getDistance ()<=.25 && getDistance () >=0)
  {       
    digitalWrite(red, HIGH);
    getDistance(); 
    analogWrite (buzzer,128);
    delay (100);
    analogWrite (buzzer,0);

  } 
  else { 
    digitalWrite(red, LOW);
    analogWrite (buzzer,0);
  }


  if(getDistance ()<=.5 && getDistance () >=.25) 
  {       
    digitalWrite(yellow, HIGH); 
    getDistance(); 
  } 
  else {  
    digitalWrite(yellow, LOW); 
  }



  if(getDistance ()<=1 && getDistance () >=0.5)
  {       
    digitalWrite(green, HIGH);

    buzz (100);
    getDistance ();
  } 
  else { 
    digitalWrite(green, LOW);
  }


  Serial.print(getDistance());     
  Serial.print("m");          
  Serial.println();            
  delay (2000);                

}

float getDistance ()
{
  digitalWrite(triggerright, LOW);    
  delayMicroseconds(2);
  digitalWrite(triggerright, HIGH);   
  delayMicroseconds(5);
  digitalWrite(triggerright, LOW);    


  float distance = pulseIn (echoright, HIGH);  

  return (distance) / 2938 / 2;
}


void buzz(int interval)
{
  unsigned long currentMillis = millis();
  if(currentMillis - previousMillis > interval) {
    previousMillis = currentMillis;   
    if (buzzerState == 0){
      buzzerState = 110;
    } 
    else {
      buzzerState = 0;
    }
    analogWrite(buzzer, buzzerState);
    
  }
}

but how can i get it to be more frequent?