HI guys here i am using pic16f877a microcontroller to generate 5 second delay using timer1

// CONFIG

#pragma config FOSC = HS    // Oscillator Selection bits (HS oscillator)

#pragma config WDTE = OFF    // Watchdog Timer Enable bit (WDT disabled)

#pragma config PWRTE = OFF   // Power-up Timer Enable bit (PWRT disabled)

#pragma config BOREN = OFF   // Brown-out Reset Enable bit (BOR disabled)

#pragma config LVP = OFF    // Low-Voltage (Single-Supply) In-Circuit Serial Programming Enable bit (RB3 is digital I/O, HV on MCLR must be used for programming)

#pragma config CPD = OFF    // Data EEPROM Memory Code Protection bit (Data EEPROM code protection off)

#pragma config WRT = OFF    // Flash Program Memory Write Enable bits (Write protection off; all program memory may be written to by EECON control)

#pragma config CP = OFF     // Flash Program Memory Code Protection bit (Code protection off)

// #pragma config statements should precede project file includes.

// Use project enums instead of #define for ON and OFF.

#include <xc.h>

#define _XTAL_FREQ 20000000

void timer1isr();

void delay(int a);

int main()

{

  TRISD=0X00;

  while(1)

  {

    PORTD=0Xff;

    delay(5);//delay for 5 seconds;

    PORTD=0X00;

    delay(5);

}

}

void timer1isr()//for creating 1 second delay;

{

  int i;

  TMR1ON=0X01;

 for(i=0;i<82;i++) {

  TMR1H=TMR1L=0;

  while(!TMR1IF);

  TMR1IF=0;  

 }

}

void delay(int a)

{

 int j=0;

 for (j=0;j<=a-1;j++)

 {

   timer1isr();

 }

}