You are at carltaylor.eu/map.php?x=100&y=200 just like you want.
The 'correct' way to pass variables into Flash is via FlashVars.
The wonderful SWFObject allows you to do it very easily, as it can automatically fetch your variables from the url, - like shown on the other post and its links - and pass them into Flash.
Yes. That's it!
You may adjust the background color and the Flash Player version you're targeting.
You're welcome.
If you aren't familiar already with it already, take some time to read the article on SWFObject as it's very useful.
It does simplify things and solves some 'problems'.
Added code tags to your post as it makes code more readable.