I am trying to display a jquery dialog box on click on an asp button. When I click on the button 'close' appears together with the dialog title but it does not look like a dialog box and it disappears after about a second. Can someone please help me?

JQuery Code - GenerateDialog.js:

$(document).ready(function() {
    $.ui.dialog.defaults.bgiframe = true; 

function CreateDialog() {

aspx code:
<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Default.aspx.cs" Inherits="cDevelopment._Default" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
    <script type="text/javascript" src="../js/jquery.min.js"></script>
     <script type="text/javascript" src="../js/jqueryui.min.js"></script>
    <script type="text/javascript" src="../js/GenerateJDialog.js"></script>
    <form id="form1" runat="server">
            <asp:Button ID="b1" runat="server" Text="Button" OnClientClick="CreateDialog()"/>
            <div id="jDialog" title="Alert">

I am using jquery 2.6.1 and jqueryui 1.7.1


Kind Regards