$(document).on('change', '#file-uload-main', function (event) {
       
        var files = event.target.files;
        var file, date;
        var filedata1 = new DataTransfer();
        var x = 0;
        var cou = 0;

      

        for (var i = 0; i < files.length; i++) {
            x++;
            file = files[i];
            var resource_image;
            date = new Date();
            var file_size = file.size;
            var file_type = file.type;
            var convert_file_size = (file_size / (1024 * 1024)).toFixed(2);
            var test_value = $("#file-uload-main").val();
            var extension = test_value.split('.').pop().toLowerCase();
            if ($.inArray(file_type, ['image/jpeg', 'image/jpg', 'image/png', 'application/pdf']) == -1) {
                $('.file-require-tut').slideDown(500);
                var outofmaxsize = "Tệp tin <strong>" + file.name + "</strong> không hợp lệ";
                $('.out_of_max_size').append(`
                    <div class="error_file_container">
                     <p style="color :red ;line-height:22px;" class="error_file_append">`+ outofmaxsize + `</p>
                     <div class="delete-file-upload-error">
                       <img src="../images/admin_img/xoa.svg" alt="xoá tác vụ">
                     </div>
                    </div>
                `);
            } else {
                if (convert_file_size <= 5) {
                    $('.file-require-tut').show();
                    if (file_type == 'image/jpeg' || file_type == 'image/jpg' || file_type == 'image/png') {
                        resource_image = 'png-ft-img-file.svg';
                    } else if (file_type == 'application/pdf') {
                        resource_image = 'pdf-ft-img-file.svg';
                    }
                    $('.upload_items_' + $(this).data('id')).append(
                        `<li class="upload_item_li" data-id="` + file.name + `" data1="` + x + `">
                            <span><img src="../images/admin_img/`+ resource_image + `" alt="tải lên tệp tin" class="img-ft-file-upload"></span>
                            <span>
                                <p class="file-upload-name" class="font_dam">` + file.name + `</p>
                                <ul>
                                    <li class="last-date-modify">` + date.toLocaleDateString('vi-VN') + `</li>
                                    <li>` + date.toLocaleTimeString('vi-VN') + ` </li>
                                    <li class="file-upload-size">` + convert_file_size + ` Mb /5 Mb</li>
                                </ul>
                            </span>
                            <div class="delete-file-upload" data="`+ i + `" >
                                <img src="../images/admin_img/xoa.svg" alt="xoá tác vụ">
                            </div>
                    </li>`);
                    cou += Number(convert_file_size);
                    filedata1.items.add(file);
                }
                else {
                    $('.file-require-tut').show();
                }
            }
        }
    });