How do I get App_Themes location in a html file using javascript

I am looking for a solution in javascript, where I can get the location to App_themes\Theme folder which contains theme files in asp.net. For example why this isn't so easy is because when the virtual directory has been mapped directly to d开发者_如何学Comain name then it would be domainname\App_Themes\themename\default.css but if virtual directory has been mapped to something else then how will I differentiate between the name and it could also be directory name?

If your app is in the same virtual directory as the theme file, then you can just use relative path.

If your app is in a different virtual directory, then no way to auto change the path when the virtual directory changed.