Determine if its a leap year

// Determine if a year is a leap year or not.

#include <iostream>
#include <string>

using namespace std;

// This function returns true if a
// year is a leap year, otherwise false.
int is_leap(int year)
{
    if (year % 100 == 0) // If it's divisible by 100,
    {
        if (year % 400 == 0) // And divisible by 400.
        {
            return true; // It's a leap year.
        }
        else // If it's divisible by 100 but not 400,
        {
            return false; // It's not leap year.
        }
    }
    else // Else if it's not divisible by 100,
    {
        if (year % 4 == 0) // If it's divisible by 4,
        {
            return true; // It's a leap year.
        }
        else // Else if it's not divisible by 4,
        {
            return false; // It's not a leap year.
        }
    }
}

int main()
{
    bool successful_conversion = false; // Is the user's input an integer?
    bool is_a_leap_year = false; // Is the year a leap year?
    string year; // User's input.
    int converted_srting_input = 0; // User's input converted to an integer.

    cout << "This program will determine if a year is a leap year.\n";

    while (!successful_conversion) // While the user's input is not an integer,
    {
        cout << "\nWhat year do you want to check? ";
        cin >> year; // Get user input.

        try // Prepare to handle if the user's input is not an integer.
        {
            converted_srting_input = stoi(year); // Try to convert input to integer.
            successful_conversion = true; // Input was an integer.
        }
        catch (...) // If the string input can't be converted to an integer,
        {
            cout << "Something is wrong with the year you entered.\n"
                "Try again.\n\n";
        }
    }

    is_a_leap_year = is_leap(converted_srting_input); // Determine if it's a leap year.

    // Announce the result.
    cout << "\nThe year " << converted_srting_input << " is ";
    if (!is_a_leap_year)
    {
        cout << "not ";
    }
    cout << "a leap year.\n";

    return 0; // End the program.
}