Im using the following:
url=location.href
fname=url.match(/.*\/(.*)\./)[1]
document.body.className=fname
This takes part of the URL and adds a class to the <body> tag with the text extracted from the URL.
However the problem with this method is the class only gets applied providing doesnt already have a class assigned.
Im really looking for something similar to the JQUERY .addClass function so body becomes:
<body class="originalClass filenameClass">
...
</body>