#include <Servo.h>

Servo myservo;  // create servo object to control a servo
// twelve servo objects can be created on most boards

int potpin = 0;  // analog pin used to connect the potentiometer
int val;        // variable to read the value from the analog pin

void setup() {
  // put your setup code here, to run once:
  // attaches the servo on pin 9 to the servo object
  myservo.attach(9);  

}

void loop() {
  // put your main code here, to run repeatedly:
  // reads the value of the potentiometer (value between 0 and 1023)
  val = analogRead(potpin);
  // scale it to use it with the servo (value between 0 and 180)            
  val = map(val, 0, 1023, 0, 180);
  // sets the servo position according to the scaled value     
  myservo.write(val);
  // waits for the servo to get there                  
  delay(15);                           
}