int motorPin = 9;

int buttonPin1 = 2;
int buttonPin2 = 3;

int variableSpeed = 0;

void setup()
{
  pinMode(motorPin, OUTPUT);
  pinMode(buttonPin1, INPUT);
  pinMode(buttonPin2, INPUT);
  Serial.begin(9600);
}

void loop ()
{
  if(digitalRead(buttonPin2) == 1)
  {
    Serial.println("B1");
    motorSpeed(50);
  }
  else if (digitalRead(buttonPin1) == 1)
  {
    Serial.println("B2");
    motorSpeed (-50);
  }
  delay(100);
  analogWrite(motorPin, variableSpeed);
}
int motorSpeed (int motorspeed){
  variableSpeed = motorspeed + variableSpeed;

  if (variableSpeed > 255) {
    variableSpeed = 255;
  }
  else if (variableSpeed < 0) {
    variableSpeed = 0;

  }

  return variableSpeed;
}