#include <Servo.h>
Servo myservo;
int pos = 0;

void setup() {
 myservo.attach(7);
}

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);
  } 
}