Can I make simplemodal contact form post across domains?

I'm using the SMCF Wordpress plugin on this site: http://fingelly.com/

As you can see it uses ajax to post the form fields to get mailed and then updates the modal.

Some of the nav options at the site take you to a 3rd party IDX (real estate listings) provider. For example click on the tabs marked agents and the url changes to fingelly.idxre.com...

As you can see the html is customizable there... I had tried adding the same simple modal contact form to my t开发者_StackOverflow中文版emplate there but encountered a problem because I cannot post using ajax to my wordpress driven site from this other domain.

I understand this limitation is for security reasons to prevent xss. How would you suggest working around it in this case?

For now we've simply removed the contact tab.

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If you just need to send information to the server and not worry about the response, you create a hidden iframe on the page and post the data there. You could also make a JSONP call if the data would fit in a GET.