When working with the new URL routing portion of the ASP.NET 4.0, there is a gotcha that needs to be worked around.
Assume a website with the following structure:
~/Images/header.jpg
~/Stylesheets/style.css
~/Scripts/scripts.js
~/Driver/Details.aspx
~/Default.aspx
Also assume you use URL routing to change the structure of the page
/Driver/Details/{CustomerNumber} maps to ~/Driver/Details.aspx
When including the <script> and <link> tags in your details.aspx page, if you use the normal "../Stylesheets/style.css", then the stylesheets wont load, nor will the scripts because the page would be looking for "/Driver/Stylesheets/style.css".
Instead, use the
<%= ResolveClientURL("~/Stylesheets/style.css") %>
method to define the source of the resource.
Example:
<link href='<%= ResolveClientUrl("~/StyleSheets/ui.tabs.css") %>' rel="stylesheet"
type="text/css" />
<pre lang="xml"><script src='<%= ResolveClientUrl("~/Scripts/ui.core.js") %>' type="text/javascript"></script>