#include<Servo.h>
Servo myservo;
const int servoPin = 3;  // Servo pin
const int buttonPin = 4;
int buttonState = 0;
int directionState = 0;
int pos = 0;
void setup()
{
myservo.attach(3);
pinMode(buttonPin, INPUT);
}

void loop(){

buttonState = digitalRead(buttonPin);
   if (directionState == 0){
     if (buttonState == HIGH) {
       directionState = 1;
       for(pos = 0; pos < 180; pos+=1)
       {
         myservo.write(pos);  
         delay(1000); 
     }
     }
   } else if (directionState == 1) {
     if (buttonState == HIGH) {
       directionState = 0;   
       
        for (pos = 180; pos>=1; pos-=1)
        {    
         myservo.write(pos);
         delay(1000);
        }
      }
  }
}