Sites like this that write their code so that it'll only work in one browser make me sick. I mean, W3C was formed for a damn reason, for cryin' out loud. Not only that, this site is a facet of the U.S. government, which, unintentionally or not, can be seen as lending credence to the fact that it's "OK" to write sites like this. *sigh* Seriously, though, this is the one area in which the Netscape browser, which has the capability to use either the Firefox or the IE engine, can come into its own...

"'At this point in the process of developing the Copyright Office's system for online preregistration, it is not entirely clear whether the system will be compatible with Web browsers other than Microsoft Internet Explorer versions 5.1 and higher,' the office said in its notice."