问Jquery追加div，然后使其可调整大小和可拖动？

EN

function open_import_window(){
$('body').append('<div id="msg_bg"></div>');
$('body').append('<div id="import_box" class="import_box"><div class="title_bar">Import</div><div id="content_import_box"></div></div>');
$('#import_box').draggable({handle:".title_bar"}).resizable();
var window_width = $(window).innerWidth();
var import_box_left = (window_width/2)-400;
$("#import_box").css("left", import_box_left);

var window_height = $(window).innerHeight();
var import_box_top = (window_height/2)-250;
$("#import_box").css("top", import_box_top);

$.ajax({
    url: 'import.php',
    success: function(data) {
        $('#content_import_box').html(data);
        resize();
    }
});
}