add this line right after <?php
in remote-file-copy.php
header("Access-Control-Allow-Origin: *");
this will tell the browser to allow javascript from other origins to access content from your php file , if you only want to allow from your site you can also do this:
header("Access-Control-Allow-Origin: http://yourmaindomain.com");
more reading on this: MDN ,enable-cors.org, another question
see also : chrome-blocks-different-origin-requests