Program to encrypt and decrypt a file

Program:

#include<stdio.h>
#include<conio.h>
void main()
{
    FILE *fptr;
    char c;
    clrscr();
    printf("Enter the text to be stored in the file.\n");
    printf("Use ^Z or F6 at the end of the text and press ENTER : \n\n");
    fptr = fopen("ENCDEC.DAT","w");
    while((c = getchar()) != EOF)
    fputc(c, fptr);
    fclose(fptr);
    printf("\n\nData output in encrypted form : \n\n");
    fptr = fopen("ENCDEC.DAT", "r");
    while((c = fgetc(fptr)) != EOF)
    printf("%c", c + 1);
    fclose(fptr);
    printf("\n\nData output in decrypted form : \n\n");
    fptr = fopen("ENCDEC.DAT", "r");
    while((c = fgetc(fptr)) != EOF)
    printf("%c", c);
    fclose(fptr);
    getch();
}

Output:

Enter the text to be stored in the file.
Use ^Z or F6 at the end of the text and press ENTER :
Computer Practice - II
D.D. Publications
^Z
Data output in encrypted form :
Dpnqvufs!Qsbdujdf!.!JJ
E/E/!Qvcmjdbujpot
Data output in decrypted form :
Computer Practice - II
D.D. Publications