hastin is first time

// Displays a file in either upper- or  
// lowercase depending upon a user request.
#include <fstream>
#include <iostream>
#include <string>
#include <ctype.h>

using namespace std;

// Display(): display text stream using ToFunc
// modification
void Display(ifstream &fin, int (*ToFunc)(int c)) {
    // extract and display characters one-at-a-time
    char CurrentChar;
    while (fin.get(CurrentChar)){
        // modify current character using ToFunc
        CurrentChar = (*ToFunc)(CurrentChar);
        cout << CurrentChar;
    }
    return;
}
// main(): manage file stream display
int main() {
    const int MaxFileNameSize = 256;
    // prompt and extract the name of the file
    cout << "Enter name of file: " << flush;
    char FileName[MaxFileNameSize];
    cin >> FileName;
    // make sure a valid filename was provided
    ifstream fin(FileName);
    if (fin) {
        // we have valid file, so determine the action
        cout << "Display file in uppercase or "
        << "lowercase (u, l):" << flush;
        char reply;
        cin >> reply;
        // display file according to request
        if (reply == 'l')
            Display(fin, tolower);
        else if (reply == 'u')
            Display(fin, toupper);
        else {
            cerr << "Bad request" << endl;
            return 1;
        }
    }
    else {// process invalid filename
        cerr << "Invalid file name: " << FileName
         << endl;
        return 1;
    }
    return 0;
}