How we can nevigate when we are using Embedding UI in HTML

Hi i am new to vaadin i have 1 problem i am Embeeding my UI in HTML it works but when we click on buttton from UI it shows error UIDL could not be read from server
my code :

<?xml version="1.0" encoding="UTF-8" ?> Embedding a Vaadin Application in HTML Page

Embedding a Vaadin UI

This is a static web page that contains an embedded Vaadin application. It's here:

<!-- Optional placeholder for the loading indicator -->
<div class="v-app-loading"></div>

<!-- Alternative fallback text -->
<noscript>You have to enable javascript in your browser to
          use an application built with Vaadin.</noscript>

Please view the page source to see how embedding works.