Get Object by classid

How do I detect if an object is loaded ?, for example my javascript code is:

document.writeln("\<OBJECT classid=\"clsid:12510606-30FA-11D2-F383-434553540000\"");
etc

Also, when I give it an id it doesn't recognize it, i.e I can't see it in the DOM inspector. So I need to detect by classid, not id.

what if you tried something like:

document.getElementsByTagName("object")[0].yourAttribute

Eric

Thanks, I found the classid by using
alert(document.getElementsByTagName("object")[0].classid);

The only catch is that I want to know if the Add-on is loaded or not.
When I run the above code it reports the classid whether it's loaded or not.

But I found an answer:
http://developer.apple.com/internet/webcontent/detectplugins.html