Fading LED using Arduino

// C++ code
//
int led =6;
int brightness =0;
int fadeAmount =5;
void setup()
{
  pinMode(led, OUTPUT);
}

void loop()
{
  analogWrite (led, brightness);
  brightness= brightness + fadeAmount;
  if (brightness <=0 || brightness >=255){
    fadeAmount =-fadeAmount;
  }
  delay(30);
}