RFID Starter Kit Problem ID-12

hi! XD

i change program by http://forum.arduino.cc/index.php?action=profile;u=62243
i want to display "Your Card is False "to serial once with a false card,
but the “Your Card is False” display many times at Serial Monitor.
anyone can help ? =(

#include <SoftwareSerial.h>

const int SerInToArdu=7; //Defines pin data passes
//to Arduino over from RFID reader
const int SerOutFrmArdu=3; //Not used, but
//“fills” a parameter in the set up of
String FullCode;

SoftwareSerial mySerialPort(SerInToArdu,SerOutFrmArdu);
// Creates serial port for RFID reader to be attached to.
// Using pins 0 and 1 is problematic, as they are also
// connecting the development PC to the Arduino for
// programming, and for the output sent to the serial
// monitor.

void setup()
Serial.begin(9600);//For access to serial monitor channel
Serial.println(“Please Scan Card”);

void loop()
int incomingByte=0;//create and initialize a local variable

//The “then” part of the following will only execute
// after the RFID reader has sent something to the Arduino
if (mySerialPort.available() > 0) {

// read the incoming byte from the serial buffer
incomingByte = mySerialPort.read();
// show what was received
//Serial.print(incomingByte, DEC);
//Serial.print(’ ');
FullCode = FullCode + " " + incomingByte;
if (FullCode == 124){
Serial.print("The Full Code is - ");
if (FullCode == FullCode)
Serial.println(“Your Card Is True”);
FullCode = “”;
if(FullCode != 124);
Serial.println(“Your Card Is False”);
FullCode = “”;
FullCode = “”;