$("button.send-form-data").click(function () {
    var book = $("#form-book").val();
    var price = $("#form-price").val();
    var writer = $("#form-writer").val();
    $.post("any_script.php",
    {
        book: book,
        price: price,
        writer: writer
    })
    .done(function (data) {
        alert (data);
    })
    .fail(function () {
        alert ('Error!!!');
    });
});

 

Vlastimil Pošmura, 2019