Question

Sorry I’m beginner, can somebody help me out?

<script>
var iW = $(document).width();

$(function() {
//single book
$('#mybook').booklet({
   next: '#custom-next',                
    prev: '#custom-prev',
     keyboard: true,
    width:   return iW, // here is the problem! It doesn't work.
    height: 200

});

//multiple books with ID's
$('#mybook1, #mybook2').booklet();

//multiple books with a class
$('.mycustombooks').booklet();

});

</script>

Answer 1

return there is unnecessary. You just need width: iW.

That said, you should also bring the call to $(document).width() within the ready block.

$(function () {
    var iW = $(document).width();

    //single book
    $('#mybook').booklet({
        next: '#custom-next',
        prev: '#custom-prev',
        keyboard: true,
        width: iW,
        height: 200

    });

    //multiple books with ID's
    $('#mybook1, #mybook2').booklet();

    //multiple books with a class
    $('.mycustombooks').booklet();

});