int ledStatus = 0;

//Pin assignment
byte ledPin=12;

void setup()
{
  Serial.begin(9600);
  pinMode(ledPin, OUTPUT);
}
void loop()
{
     Serial.print("Do you want on or off?");
     while(Serial.available()){};
     ledStatus = Serial.parseInt();
      if(ledStatus == 1){
        digitalWrite(ledPin, HIGH);
        Serial.print("You chose on");
      }
      else if (ledStatus == 0){
        digitalWrite(ledPin, LOW);
        Serial.print("You chose off");
      }
      }