4-LED BT Control

//#include <SoftwareSerial.h>
//int bluetoothTx = 12;//bluetooth module terminal TX
//int bluetoothRx = 11;//bluetooth module terminal RX
//SoftwareSerial bluetooth(bluetoothTx, bluetoothRx);

void setup() {
 Serial.begin(9600);
// bluetooth.begin(9600);

 pinMode(7, OUTPUT);
 pinMode(8, OUTPUT);
 pinMode(9, OUTPUT);
 pinMode(10, OUTPUT);
 digitalWrite(7, LOW);
 digitalWrite(8, LOW);
 digitalWrite(9, LOW);
 digitalWrite(10, LOW);
  }


void loop() {
   if(Serial.available()>0)
   {
      char x = Serial.read();
      switch(x)
      {
        case 'a': digitalWrite(7, HIGH);digitalWrite(8, HIGH);digitalWrite(9, HIGH);digitalWrite(10, HIGH);break;
        case 'r': digitalWrite(7, HIGH); /*Serial.println("Red LED is on");*/ /*bluetooth.print('R');*/ break;
        case 's': digitalWrite(7, LOW);break;
        case 'g': digitalWrite(8, HIGH);break;
        case 'h': digitalWrite(8, LOW);break;
        case 'y': digitalWrite(9, HIGH);break;
        case 'z': digitalWrite(9, LOW);break;
        case 'b': digitalWrite(10, HIGH);break;
        case 'c': digitalWrite(10, LOW);break;
        case 'x': digitalWrite(7, LOW);digitalWrite(8, LOW);digitalWrite(9, LOW);digitalWrite(10, LOW);break;
        default : break;
      }
        delay(50);
   } //end switch
} //end loop