Javascript does not work with Document Declaration

[thisisnotmyname]

http://www.dynamicdrive.com/dynamicindex1/staticmenu.htm

When I place the "float menu (found at the url above)" script on my webpage, it will only work when I do not place a Document Declaration above the header of my html document. How can I get it to work even when there is a document delcaration?

Thanks for any help.