If this page is intended to be accessible to everyone, you don't need to take any action. Otherwise please follow the guidelines for different architectures below in order to set this header and permit outside domain.
Merge the following xml into the web.config file at the root of your application or site:
<?xml version="1.0" encoding="utf-8" ?>
<add name="Access-Control-Allow-Origin" value="domain" />
If you don't have access to configure IIS, you can still add the header through ASP.NET by adding the following line to your source pages: