Access Control Allow Origin Error

I cannot seem to get this to work and believe the problem stems for the following error I am seeing in Chrome:

No 'Access-Control-Allow-Origin' header is present on the requested resource.

Some background that may help in a solution:

The drupal site I am working on is https://www.example.com/drupal.

The error I receive also states: Origin 'https://www.example.com' is therefore not allowed access.

My goal is to get the contact page to show in a modal.

Has anyone else come across this issue and have a solution?

Thanks!