Weird Scroll Window and Broken Site

Hi, I’m experiencing a very strange issue. My site has been running well for the last several months, and then just yesterday this strange little scroll window appeared on my site. It is hard to see what’s inside but there is text which says:

Not Found The requested URL /dtd.php was not found on this server.

Now I cant click on anything. Links, Images, nothing works. The links to pages at the top have even disapeared.

I have tried everything, and compared every bit of code to my other, basically identical web site which is running fine on a different server.

Can anyone help me figure this out?

The afflicted site is: http://emiliemadi.com/em/?page_id=5

Thank you!