#include<Servo.h>
Servo myServo;
int pos;
void setup() {
  // put your setup code here, to run once:
  Serial.begin(9600);
  myServo.attach(9);
  myServo.write(0);
}

void loop() {
  Serial.println("enter position: ");    
  while (Serial.available()==0){}          
  pos = Serial.parseInt(); 
  if(pos>=0&&pos<=180){
     myServo.write(pos);
     Serial.print("Turned to ");                   
     Serial.println(pos);
     Serial.flush();               
     }
     else Serial.println("invalid position");
  }