H bridge code

const int MD = 8;
const int MS = 9;
void setup() {
  pinMode(MD, OUTPUT);
  pinMode(MS, OUTPUT);
  digitalWrite(MD, LOW);
  digitalWrite(MS, LOW);
  Serial.begin(9600);
  do
  {
    Serial.println("Input 1 - 9");
  }
  while(!Serial);
}

void loop() {
  if(Serial.available() > 0)
  {
    int userInput = Serial.parseInt();
    switch(userInput)
    {
      case 1:
      {
        digitalWrite(MD, 0);
        analogWrite(MS, 0);
        Serial.println("OFF");
        break;
      }
      case 2:
      {
        digitalWrite(MD, 1);
        analogWrite(MS, 50);
        Serial.println("CW SLOW");
        break;
      }
      case 3:
      {
        digitalWrite(MD, 1);
        analogWrite(MS, 100);
        Serial.println("CW MED");
        break;
      }
      case 4:
      {
        digitalWrite(MD, 1);
        analogWrite(MS, 255);
        Serial.println("CW FAST");
        break;
      }
      case 5:
      {
        digitalWrite(MD, 0);
        analogWrite(MS, 50);
        Serial.println("CCW SLOW");
        break;
      }
      case 6:
      {
        digitalWrite(MD, 0);
        analogWrite(MS, 100);
        Serial.println("CCW MED");
        break;
      }
      case 7:
      {
        digitalWrite(MD, 0);
        analogWrite(MS, 255);
        Serial.println("CCW FAST");
        break;
      }
//      default:
//      {
//        digitalWrite(MD, 0);
//        analogWrite(MS, 0);
//        Serial.println("DEFAULT CASE");
//        break;
//      }
    }
  }
}