Ammended File->uppercase

#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>
#include <string.h>

int i = 0, chars = 0;

main()
{
    char ch, fileName[140];
    FILE*tempFile;
    FILE*inFile;

    printf("Files available to be opened: \n");
    printf("\nfirstoption.txt");
    printf("\nsecondoption.txt");
    printf("\n\nPlease type the name of the file, with extension, you'd like to open: ");
    gets(fileName);

    inFile = fopen(fileName, "r+");
    tempFile = fopen(fileName,"r+");

    inFile = fopen(fileName, "r+");
    if (inFile == NULL)
    {
        printf("\nThe file could not be opened, please check that the file exists.");
    }
    else
    printf("The file was successfully opened!\n\n");

    while((ch=fgetc(inFile)) != EOF) {
        chars = chars + 1;
        fputc(toupper(ch), tempFile);
    }

    fclose(inFile); fclose(tempFile);
    printf("The characters in the file you chose have been changed.\nAll characters should be uppercase.\n");
}