Arduino interfacing cSharp

#define ledPin 2

void setup() {
    Serial.begin(9600);
    pinMode(ledPin, OUTPUT);
}

void loop() {
    char rx_data = Serial.read();
    switch(rx_data) {
        case 'ON':
            digitalWrite(ledPin, HIGH);
            Serial.println("Led is turned on!");
            break;
        case 'OFF':
            ditialWrite(ledPin, LOW);
            Serial.println("Led is turned off!");
            break;
    }
}