Books database Learn programming C#

using System;
public class exercise82
{
    struct book
    {
        public string title;
        public string author;
    }

    public static void Main()  
    {
        int capacity = 1000;  
        book [] books =new book [capacity];  
        bool repeat=true;  
        string option;     
        int amount=0;      
        string search;     
        bool found;       

        do
        {
            Console.WriteLine();
            Console.WriteLine("Books database");
            Console.WriteLine();
            Console.WriteLine("1- Add a new book");
            Console.WriteLine("2- Display all books");
            Console.WriteLine("3- Exact search for any book");
            Console.WriteLine("4- Partial search");
            Console.WriteLine("5- Delete a book");
            Console.WriteLine("0- Exit");
            Console.Write("Enter an option: ");
            option = Console.ReadLine();

            switch (option)
            {
                case "1": // Add a new book
                    if (amount < capacity )
                    {
                        Console.WriteLine("Enter data for book {0}",amount+1);
                        Console.Write("Enter the name of the book: ");
                        books[amount].title= Console.ReadLine();
                        Console.Write("Enter the author: ");
                        books[amount].author= Console.ReadLine();
                        amount++;
                        Console.WriteLine();
                    }
                    else
                        Console.WriteLine("Database full");
                        break;


                case "2":  // Display all books
                    if (amount == 0)
                    
                    else
                    {
                        for(int i = 0;i < amount;i++)
                        Console.WriteLine("{0}: Title = {1},  Author = {2}",
                        i+1, books[i].title, books[i].author);
                        Console.WriteLine();
                    }
                    break;
                case "3":  // Exact search
                    Console.WriteLine("Enter the name of the book");
                    search=Console.ReadLine();
                    found = false;

                    for (int i = 0;i < amount;i++)
                        if(books[i].title==search)
                    {
                        Console.WriteLine("Book {0} found",books[i].title);
                        found = true;
                    }

                    if (! found)
                    Console.WriteLine("Not found!");
                    Console.WriteLine();
                    break;
                case "4":  // Partial search
                    Console.WriteLine("Enter the search string");
                    search = Console.ReadLine();
                    found = false;

                    for (int i = 0;i < amount;i++)
                    if(books[i].title.ToUpper().Contains(search.ToUpper())
                        books[i].author.ToUpper().Contains(search.ToUpper()))
                    {
                        Console.WriteLine("{0} found in {1}",
                        search, books[i].title);
                        found = true;
                    }

                    Console.WriteLine();

                    if (! found)
                        Console.WriteLine("Not found!");
                        break;
                case "5":  // Delete
                    if (amount == 0)
                        Console.WriteLine("No data to delete");
                    else
                    {        
                        Console.WriteLine(
                        "Enter the number of book to delete (1 to {0})", amount);
                        int posToDelete = 
                        Convert.ToInt32(Console.ReadLine()) - 1;
                        for (int i = posToDelete; i < amount - 1; i++)
                        books[i] = books[i+1];
                        amount--;
                    }
                    break;
                case "0":  // End
                    repeat=false;
                    break;
                    default:
                    Console.WriteLine();
                    Console.WriteLine("Wrong option. Please re-enter\n");
                    break;
            }
        }
        while(repeat);
    }
}