I am using  JQuery dialog box. It is not showing close icon.

Below is the code:

open_menu.js

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<script>

            $(function () {

                $("#menu-dialog1_UC1").dialog({

                    autoOpen: false,

                    width: 350,

                    height: 250,

                    title: "Menu for UC1",

                    position: "center"

                });

                $("#open-menu-dialog1_UC1").click(function () {

                    $("#menu-dialog1_UC1").dialog("open");

                });

            });

        </script>

index.html

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<script src = "scripts/jquery-1.10.2.js"></script>

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

<button id="open-menu-dialog1_UC1">

How to bring that close icon. Kindly suggest...