#include <Servo.h> 
 const int servoPin = 8;  // Servo pin
 const int buttonPin = 9;  // Pushbutton pin
 int buttonState = 0; 
 int directionState = 0; 
 Servo myservo; 
 int pos = 0;
 
void setup() {
   myservo.attach(8);
   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(15);  // waits 15ms to reach the position 
       }
     }

   } else if (directionState == 1) {
     if (buttonState == HIGH) {
       directionState = 0;   
       
      for (pos = 180; pos>=1; pos -=1)
       {
         myservo.write(pos);
         delay(15);
       }
     }
   }
 }