 <p>If you have control over both domains, you can try a cross-domain scripting library like <a href="http://easyxdm.net/" rel="nofollow noreferrer">EasyXDM</a>, which wrap cross-browser quirks and provide an easy-to-use API for communicating in client script between different domains using the best available mechanism for that browser (e.g. <a href="https://developer.mozilla.org/en/DOM/window.postMessage" rel="nofollow noreferrer">postMessage</a> if available, other mechanisms if not). </p> <p>Caveat: you need to have control over both domains in order to make it work (where "control" means you can place static files on both of them). But you don't need any server-side code changes.</p> <p>In your case, you'd add javascript into one or both of your pages to look at the location.href, and you'd use the library to call from script in one page into script in the other. </p> <p>Another Caveat: there are security implications here-- make sure you trust the other domain's script!</p>