ARDUINO beginner's Project | Servo

#include <Servo.h>

Servo myservo; 

int pos = 0;   

void setup() {
  myservo.attach(9); //pin ~9
}

void loop() {
  for (pos = 0; pos <= 180; pos += 1) { 
    myservo.write(pos);              
    delay(15);                      
  }
  for (pos = 180; pos >= 0; pos -= 1) {
    myservo.write(pos);              
    delay(15);                     
  }
}