我想将base_url从控制器手册发送到book.js

这是我在book.js中的函数

function loadPage(page, pageElement) {

    // Create an image element
    var img = $('<img />');

    img.mousedown(function(e) {
        e.preventDefault();
    });

    img.load(function() {
        // Set the size
        $(this).css({width: '100%', height: '100%'});

        // Add the image to the page after loaded
        $(this).appendTo(pageElement);

        // Remove the loader indicator
        pageElement.find('.loader').remove();
    });

    // MY PROBLEM is here !!! Load the page
    // img.attr('src', '../../_library/book/samples/magazine/pages/' +  page + '.jpg');
    img.attr('src', '<?php echo base_url($source) ?>' +  page + '.jpg');

    loadRegions(page, pageElement);

}