How to change jquery dialog close button position

<%@ Page Title="" Language="VB" MasterPageFile="~/MasterPage.master" AutoEventWireup="false" CodeFile="Default4.aspx.vb" Inherits="Default4" %>

<asp:Content ID="Content1" ContentPlaceHolderID="head" runat="Server">
    <script src="Scripts/jquery-2.1.4.min.js"></script>

    <script src="Scripts/jquery-ui-1.11.4.js"></script>

    <link href="Content/themes/base/all.css" rel="stylesheet" />

    <script type="text/javascript">
        function ShowPopup(message, titlea) {
            $(function () {
                $("#dialog").html(message);
                $("#dialog").dialog({
                    title: titlea,
                    modal: true
                     ,
                    buttons: {
                        "إغلاق": function () { $(this).dialog('close'); }
                    }
                });
            });
        };


    </script>

    <style type="text/css">
        .ui-dialog .ui-dialog-title {
            direction: rtl;
            float: right;
            margin: 0.1em 0 0.2em 16px;
        }

        .ui-dialog .ui-dialog-titlebar-close {
            left: 0.3em;
        }

        .ui-dialog .ui-dialog-buttonpane .ui-dialog-buttonset {
            float: none;
        }

        .ui-dialog .ui-dialog-buttonpane {
            text-align:left; /* left/center/right */
        }
    </style>
</asp:Content>
<asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder1" runat="Server">
    <div id="dialog" style="display: none; direction: rtl;"></div>

    <asp:Button ID="btnShowPopup" runat="server" Text="Show Popup" OnClick="btnShowPopup_Click" />


</asp:Content>

Protected Sub btnShowPopup_Click(sender As Object, e As System.EventArgs) Handles btnShowPopup.Click
    Dim message As String = "هذه تجربة لرسالة بالعربية"
    Dim title As String = "عنوان الرسالة"
    ClientScript.RegisterStartupScript(Me.GetType(), "Popup", "ShowPopup('" + message + "', '" + title + "');", True)
End Sub