//menu.cpp

#include<iostream>

using namespace std;

int main() {

        int i, sum, counter, j;
        bool flag;

        int choice;
       
        do
        {
                cout    << endl
                        << "Choose 1 to search by Title.\n"
                        << "Choose 2 to search by Author.\n"
                        << "Choose 3 to search by ISBN.\n"
                        << "Choose 4 to exit this program.\n"
                        << "Enter your choice and press return:  ";
                cin >> choice;
               
                switch (choice)
                {
                        case 1:
                                // code for search by title
                                cout << "Search by Title.\n";
                                break;
                        case 2:
                                // code for search by author
                                cout << "Search by Author.\n";
                                break;
                        case 3:
                                // code for search by ISBN
                                cout << "Search by ISBN.\n";
                                break;
                        case 4:
                                // code for exit
                                cout << "End of program.\n";
                                break;
                        default:
                                // code for search by author
                                cout << "Invalid choice, please try again.\n";

                }

               
        }while(choice != 4);


        return 0;
}