#include <Servo.h> 

Servo myServo;        
int pos = 0;            
int potPin = A0;        
int potValue = 0;       
int outputValue = 0;    

void setup() 
{
  myServo.attach(9);  
  myServo.write(pos);  
  delay(10);
} 

void loop() {
  potValue = analogRead(potPin);
  pos = map(potValue, 0, 1023, 0, 180);
  myServo.write(pos);
  delay(30);
}