Displaying xbee received character to LCD

Projects Networking, Protocols, and Devices
1

Using the dfrobot interface Xbee USB Adapter (FTDI Ready) - DFRobot i wanted to test the combination xBee ==> LCD (I2C)

the program should display the xbee received characters on the LCD.
But thers nothing visible on the LCD.
The connected LCD is working (Tested with a different sketch) and the two used xBee's are communicating with each other (Tested with two x-ctu terminals.

#include <Wire.h> 
#include <LiquidCrystal_I2C.h>
#include <SoftwareSerial.h>
#define rxPin 2
#define txPin 3
#define ledPin 13
SoftwareSerial xbee =  SoftwareSerial(rxPin, txPin);

LiquidCrystal_I2C lcd(0x20,16,2);  // set the LCD address to 0x20 for a 16 chars and 2 line display

void setup()
{
  lcd.init();                      // initialize the lcd 
  lcd.backlight();
  pinMode(rxPin, INPUT);
  pinMode(txPin, OUTPUT);
  xbee.begin(19200);
  Serial.begin(9600);
}

void loop()
{
  // when characters arrive over the serial port...
  if (Serial.available()) {
    while (xbee.available() > 0) {
      // display each character to the LCD
      lcd.write(xbee.read());
    }
  }
}

Anny suggestions on how to get this running

2 
  if (Serial.available()) {
    while (xbee.available() > 0) {
      // display each character to the LCD
      lcd.write(xbee.read());
    }
  }

If there is data on the Serial port, read the data on the xbee port? What is the relationship between Serial data and xbee data?