Simple Word Generator Help

[iiSoMeGuY 7x]

ok, so i havent been programming in a while and am VERY rusty. i can still read code easily, but i cant remember much when i try to write code on my own, soooooo....

i need to make a program that takes a line of up to 20 letters entered by the user and generate ALL possible outcomes of the scrambled letters (with possible spaces). now, i started the program here:

#include <iostream>
#include <cstdlib>

using namespace std;

int main()
{
    while (1)
        {
            char menu_choice[2];

            cout << "     ::Menu:: \n\n"
                 << "1. Word Generator\n"
                 << "2. Word Scrambler\n"
                 << "3. Exit Program\n\n"
                 << "Menu Choice: ";
            cin >> menu_choice;

            if (menu_choice[0] == '1')
                {
                   char input[21];

                   system ("CLS");
                   cout << "Please enter up to 20 letters and this program will display all\npossible outcomes: ";
                   cin.getline(input,20);
                   system ("PAUSE");
                   system ("CLS");
                }

            else if (menu_choice[0] == '2')
                {
                   system ("CLS");
                   cout << "Option 2\n\n";
                   system ("PAUSE");
                   system ("CLS");
                }

            else if (menu_choice[0] == '3')
                {
                    return 0;
                }

            else if (menu_choice[0] != '3')
                {
                    system ("CLS");
                    cout << "Invalid input.\n\nPress any key to continue...";
                    system ("PAUSE");
                    system ("CLS");
                    continue;
                }

            else
                {
                    system ("CLS");
                    cout << "Invalid input.\n\nPress any key to continue...";
                    system ("PAUSE");
                    system ("CLS");
                    continue;
                }
        }
}

Any help with the word generator (menu option one) would be grately appreciated (from there i can figure out menu option two), thanks in advance.