To avoid this problem with the NavigateUrl, you need to implement it as a View State property
where the ViewState collection is used as the backing store to store the underlying value. That
way, the value is sent to the browser and back to the server with every request. To implement the
property, add the following code to the Code Behind of the Banner.ascx user control, right below
the DisplayDirection property you created earlier.
Remember, you don’t have to type all this code manually because the download that comes with
this book contains all the code shown.