GSM Modem not replying 'OK'

#include <p18f4220.h> 
#include <delays.h>  
        
#pragma config OSC = HS
#pragma config WDT = OFF 
#pragma config LVP = OFF   

void SendLCD(unsigned char Byte, unsigned char type); //send byte to print on LCD screen

#define LCD LATD //LCD Latch PORT
#define LCD_RS LATEbits.LATE0 //Register Select (0: Instruction/ 1: Data)
#define LCD_E LATEbits.LATE2 //Enable (Starts data read/write)

unsigned char
		
				//GSM byte receiving variables
				GSM_Byte_1 = 0,
				GSM_Byte_2 = 0;

void main(void) 
{	 

   ADCON1 = 0x0F; //SET ALL PORTS as DIGITAL I/O

   PORTC = 0; //intialize PORTC
   TRISCbits.TRISC6 = 0; //Serial TX
   TRISCbits.TRISC7 = 1; //Serial RX
  
   PORTD = 0; //initiallize PORTD  
   TRISD = 0x00; //LCD output	

   PORTE = 0; //initiallize PORTE    
   TRISEbits.TRISE0 = 0;  //LCD Register Select (to LCD Pin 4) 
   TRISEbits.TRISE2 = 0;  //LCD Enable (to LCD Pin 6)

   //Configuring below the USART
  
   TXSTAbits.TX9  = 0; //8bit transmission
   TXSTAbits.TXEN = 1; //transmit enabled
   TXSTAbits.SYNC = 0; //async mode
   TXSTAbits.BRGH = 1; //high speed
   TXSTAbits.TRMT = 1; //TSR empty
  
   SPBRG = 129; // 9.6kbs baud rate at 20Mhz

   RCSTAbits.SPEN = 1;  //enable serial port
   PIE1bits.RCIE = 1; //enable interrupt upon reception  
   RCSTAbits.RX9 = 0;   //8bit reception
   RCSTAbits.CREN = 1;  //enable continous receive
   RCSTAbits.ADDEN = 0; //dissable address detection (9bit)

	INTCON = 0; //Disable all interrupts
							 
	Delay10KTCYx(50); //100ms wait for LCD power up	

	//Initialize the LCD
	LCD = 0x00; //clear LCD PORTD pins
	Delay1KTCYx(25); //delay 5mS
	SendLCD(0x03,0); //Initialization command
	Delay1KTCYx(25); //delay 5mS
	SendLCD(0x03,0); //Initialization command
	Delay100TCYx(8); //delay 160uS
	SendLCD(0x03,0); //Initialization command
	Delay100TCYx(8); //delay 160uS
	SendLCD(0x3C,0); //Interface lenght is 8 bits long, 2-lines, 5x10 dots
	Delay100TCYx(8); //delay 160uS
	SendLCD(0x10,0); //Turn off LCD
	Delay100TCYx(8); //delay 160uS
	SendLCD(0x01,0); //Clear LCD	
	Delay1KTCYx(25); //delay 5mS
	SendLCD(0x06,0); //Increment the cursor after each byte written
	Delay100TCYx(8); //delay 160uS
	SendLCD(0x0C,0); //Turn on LCD, cursor off, cursor blinking off
	Delay100TCYx(8); //delay 160uS

	

	//Start up Delay	
    Delay10KTCYx(250); //500ms delay 			

	

	//Sending out 'Set FACTORY DEFAULT' Command to GSM Modem
	TXREG = 'A';       	
	while(TXSTAbits.TRMT==0); //wait until transmition is complete	 
	TXREG = 'T';       	
	while(TXSTAbits.TRMT==0); //wait until transmition is complete	
	TXREG = '&';       	
	while(TXSTAbits.TRMT==0); //wait until transmition is complete		
	TXREG = 'F';       	
	while(TXSTAbits.TRMT==0); //wait until transmition is complete
	TXREG = '[';       	
	while(TXSTAbits.TRMT==0); //wait until transmition is complete
	TXREG = '0';       	
	while(TXSTAbits.TRMT==0); //wait until transmition is complete
	TXREG = ']';       	
	while(TXSTAbits.TRMT==0); //wait until transmition is complete
	


	while(PIR1bits.RCIF == 0); //wait for data reply from GSM Modem

	GSM_Byte_1 = RCREG; //reading RCREG clears RCIF

	while(PIR1bits.RCIF == 0); //wait for data reply from GSM Modem

	GSM_Byte_2 = RCREG; //reading RCREG clears RCIF
					


	//Converting GSM data bytes to ASCII for LCD display
	GSM_Byte_1 += '0';
	GSM_Byte_2 += '0';	

	SendLCD(0x80,0); //activate LCD line 1   

	//Display GSM acknowledgement 'OK' on LCD
	SendLCD(GSM_Byte_1,1);   
	SendLCD(GSM_Byte_2,1);   
		


	while(1); //loop forever



}//end of main()

void SendLCD(unsigned char Byte, unsigned char type)
{
	
	LCD_RS = type; //Set whether it is a Command (0) or Data/Char (1)	

	Delay100TCYx(8); //delay 160uS

	LCD = Byte; //assign the new data to the LCD PORTD
	
	Delay100TCYx(8); //delay 160uS

	LCD_E = 1; //Set Enable High	
	
	Delay100TCYx(8); //delay 160uS
	
	LCD_E = 0; //Set Enable Low

}//end of SendLCD()