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?

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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.