Splitting an string coming from Serial

Using Arduino Programming Questions
22

I´ve found the real problem now. arduino.write() can only send integers. So if I am sending 'b', the arduino Serial.read() recives 98 which is the ASCII number of 'b'. So I made this code:

void loop () {
    while (serial.available() >0) {
      message = Serial.read();
      if (message>= 0 && message <=250) {
          analogWrite(pinBlue, message);// This one works perfectly
      } else if (message>250 && message<502) {
          analogwrite (pinRed,message-250);//This one doesn't work. It lights the blue LED again....
      }
  }
}

In processing I am sending 0-250 for led blue; 251-501 for led red.