public string RequestForThisBook(Book book, BookReader reader) { BookGateway aBookGateway = new BookGateway(); if (aBookGateway.CheckIfthisBookExist(book)) { if (aBookGateway.CheckBookQuantity(book) > 0) { if (aRequestGateway.RequestForThisBook(book, reader)) { return("Request Successfull"); } else { return("Error found"); } } else { return("Not Available now"); } } else { return("This book is not exist in the library"); } }