#include <Servo.h>

// declaration with object 'myservo' was also a var;
Servo servMotor;

// declaration
int potPin = A0;
int potValue; 
int angle; 

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

void loop() {
  potValue = analogRead(potPin);
  angle = map(potValue, 0, 1023, 0, 180);
  servMotor.write(angle);
  delay(15);
}