The Totally Useless But Totally Cool Christmas Box

#include <Servo.h>

Servo myservo; 

int angle = 0;

void setup() {
  myservo.attach(9);

}

void loop() {
  for(angle = 0; angle < 90; angle += 1)
{
  myservo.write(angle);
  delay(20);
}
for(angle = 90; angle >= 1; angle -= 1)
{
  myservo.write(angle);
  delay(20);
}
}