Hi,
I'm not an expert with this, but I do know what you need to do
First> here is a tool you can use to CHECK any website
http://www.unmaskparasites.com/
You simply type in after the http:// (your URL=
www.zagultrasonic.com)
And then try the 3 things in the list
I've done some screenshots of the results of running the tool on your site, but you can do it yourself.....
You can see that at least there is no malware running so people checking your site are not in any danger as of now but that can happen!
What you need to do, is to have your Hosting company help you or work with you to re-do your website> replace the code from a backup, and perhaps do something with their security or lack of security...which I cannot help you with unfortunately.
If you are hosting the site yourself> then you need to disinfect that computer, go through the site webcode and remove the Flash background....redo your stuff....and review your security.
I learned about UnamaskParasites here>
http://www.google.com/support/forum/...d376f9fe&hl=en