#include <Servo.h>
#define button 2
Servo servo;
int servo_pin=3;

boolean state=false;

void setup() {
  servo.attach(3);
  pinMode(button, INPUT_PULLUP);
}
void loop(){
  if (digitalRead((button)==LOW)){
    if (state==false){
      state=true;
      servo.write(0);
      delay(500);
    }
    else{
      state=false;
      servo.write(180);
      delay(500);
    }
  } 
}