I have awebsite, lets just call it search, in one of my browserpages open. search has a form, which when submitted runs queries on a database to which I don't have direct access. The problem with search is that the interface is rather horrible (one cannot save the aforementioned queries etc.)
I've analyzed the request (with a proxy) which is send to the server via search and I am able to replicate it. The server even sends back the correct result, but the browser is not able to open it. (Same origin policy). Do you have any ideas on how I could tackle this problem?
The answer to your question is: you can't. At least not without using a proxy as suggested in the answer by Walter, and that would mean your web site visitors would have to knowingly login to your web site using their other web site's credentials (hmm doesn't sound good...)
The reason you can't do this is related to security, if you could run a script on the tab next to the one with the site open (which is what I'm guessing you want to do), you would be able to do a CSRF attack and get any data you wish and send it to hack.com
This is, of course, assuming that there has to be a login somewhere in the process, otherwise there's no reason for you to not be able to create a simple form which posts the required query and gets the info.
If you did have access to the mentioned website, you would be able to support cross domain xml using JSONP.