motor code error

Using Arduino Motors, Mechanics, Power and CNC
39

It does not do anything

What do you mean by that?
You are entering numbers in the serial monitor, aren't you?

( when posting code, please use code tags, and please don't SHOUT)

This

 if(n >= 500)
    {
      Serial.print("writing Microseconds: ");
      Serial.println(n);
      myservo.writeMicroseconds(n);
    }
    else
    {   
      Serial.print("writing Angle: ");
      Serial.println(n);
      myservo.write(n);
    }

isn't really necessary; the Servo library does it for you - any value sent to the Servo write method greater than about 540 is automatically sent to the writeMicroseconds method.