I've been trying to send commands serially through microcontroller to rfid mifare reader module but cannot send it. Please help me if some one knows about mifare rfid reader . Here is my source code:

#include <reg51.h>
#include <string.h>

#define FREQ 11059200L
#define baudrate 19200L


sbit SIG = P3^2;
sfr lcd_data_pin=0x80;
sbit rs=P2^0;
sbit rw=P2^1;
sbit en=P2^2;

unsigned int data_out,command=0x80,temp;
unsigned char card_id[8];

void InitializeSystem();
void Sendcom(unsigned char *g_cCommand);

//Command List
unsigned char cardserno[5]={0xAA,0xBB,0x02,0x20,0x22};

bit g_bReceReady;


void delay(unsigned int count)
{
int i,j;
for(i=0;i<count;i++)
for(j=0;j<1275;j++);
}

void lcd_command(unsigned char comm)
{
lcd_data_pin=comm;
en=1;
rs=0;
rw=0;
delay(1);
en=0;
}

void lcd_data(unsigned char disp)
{
lcd_data_pin=disp;
en=1;
rs=1;
rw=0;
delay(1);
en=0;
}

lcd_string(unsigned char *disp)
{
int x;
for(x=0;disp[x]!=0;x++)
{
lcd_data(disp[x]);
}
}
void lcd_ini()
{
lcd_command(0x38);
delay(5);
lcd_command(0x0F);
delay(5);
lcd_command(0x01);
delay(5);
lcd_command(0x80);
delay(5);
}


void InitializeSystem()
{
TMOD &= 0x0F;
TMOD |= 0x21;
SCON = 0x50;
PCON |= 0x80;
TH1 = (unsigned char) (256 - ((FREQ / 192) / baudrate));
g_bReceReady = 0;
TR1 = 1;
IE = 0x90;
}



void main()
{
unsigned char j;


InitializeSystem();
lcd_ini();
lcd_command(0x81);
lcd_string("RFID TOLL");
lcd_command(0xC0);
lcd_string("COLLECTION SYST.");
delay(200);
lcd_command(0x01);
lcd_command(0x81);
lcd_string("SCAN CARD:");
delay(200);
Sendcom(cardserno);
delay(10);
lcd_command(0x01);
lcd_command(0x81);
lcd_data(card_id[j]);

}

void Sendcom(unsigned char *g_cCommand)
{
unsigned char i;
do
{
TI=0;

SBUF=g_cCommand[i];
while(!TI);
i++;
}while(g_cCommand!='�');

g_bReceReady = 1;
}

seri_int () interrupt 4 using 1
{
unsigned char j;


if(RI)
{
RI = 0;
if (g_bReceReady)
{

card_id[j]=SBUF;
RI=0;
}
}
if(TI)
{
TI = 0;
}
}