Once you run it, you will see that Default.aspx contains a RadWindow, which points to the Content.aspx. Content.aspx contains RadMultipage with several textboxes. Once the page is loaded the focus will be set to the TextBox1.
If you still have a problem, please create a simple running project, where the problem can be observed and send it to us. Once we receive it, we will do our best to help you.