#include <Servo.h>

Servo myServo;  

const int buttonPin = 2;  
const int servoPin = 9;  

int buttonState = 0;  

void setup() {
  pinMode(buttonPin, INPUT);  
  myServo.attach(servoPin);   
  myServo.write(0);           
}

void loop() {
  buttonState = digitalRead(buttonPin);  

  if (buttonState == HIGH) {  
    myServo.write(90);  
  } else {  
    myServo.write(0);  
  }
}