#include <Servo.h>;

Servo Servo;

int pos=0;

void setup(){
  Servo.attach(9);
}

void loop(){
  for (pos=0;pos<= 180; pos += 1){
   // in steps of 1 degree
   Servo.write(pos);
  delay(10);
}

for (pos = 180; pos >=0; pos -=1){
 Servo.write(pos);
 delay(10);
}
}