Theft preventer alarm project coding

#include <REGX51.H>
#include "lcd.c"

#define MAX_DELAY() delay(65000)

sbit IR_Sense=P3^1;
sbit Buz=P1^0;
sbit Load=P0^1;

void intro()
{
 lcd_init();lcd_clr();
 lcd_str("Theft Preventer ",0x80);
 lcd_str(" Security Alarm ",0xc0);
 MAX_DELAY();MAX_DELAY();
 lcd_clr();
 }

 void main()
 {
unsigned int i = 0, j= 0;
Buz = 1; Load = 0;
intro();
   while(1)
   {
if(IR_Sense == 1)
{
lcd_clr();
lcd_str("No Intruder Detet",0x80);
lcd_str("Home is Safe now ",0xc0);
delay(1000);
Buz = 1; Load = 0;
while(IR_Sense == 1);
}
else
{
lcd_clr();
lcd_str(" Intruder Deteted",0x80);
lcd_str("Home at Risk now ",0xc0);
delay(1000);
Buz = 0; Load = 1;
while(1);
}


   }
 }

LCD CODING:

#define AT89C51

#undef PIC16F877A

#ifdef AT89C51

#undef PIC16F877A

sbit rs=P0^5;

sbit rw=P0^6;

sbit en=P0^7;

#define DATA P2

#else

#define rs RB1

#define rw RB2

#define en RB4

#define DATA PORTD

#endif

#define DELAY() delay(20)

void delay(unsigned int i)

{

while(i--);

}

void lcd_cmd(unsigned char c)

{

rs=0;

DATA=c;

en=1;

DELAY();

en=0;

}

void lcd_data(unsigned char d)

{

delay(500);

rs=1;

DATA=d;

en=1;

DELAY();

en=0;

}

void lcd_clr()

{

 lcd_cmd(0x01);

 delay(100);

 lcd_cmd(0x80);

}

void lcd_init()

{

  #ifdef PIC16F877A

    TRISB1=TRISB2=TRISB4=0;

    TRISD=0;

  #endif

    rw=0;

    lcd_cmd(0x38);

    lcd_cmd(0x0c);

lcd_clr();

}

void lcd_str(const unsigned char *str, const unsigned char pos)

{

 if(pos != 0xff) /*to follow previous written position*/

  lcd_cmd(pos);

 while(*str)

  lcd_data(*str++);

 

}