[javascript] Get local href value from anchor (a) tag

I have an anchor tag that has a local href value, and a JavaScript function that uses the href value but directs it to a slightly different place than it would normally go. The tag looks like

<a onclick="return follow(this);" href="sec/IF00.html"></a>

and a JavaScript function that looks like

baseURL = 'http://www.someotherdomain.com/';
function follow(item) {
    location.href = baseURL + item.href;
}

I would expect that item.href would just return a short string of "sec/IF00.html", but instead it returns the full href, "http://www.thecurrentdomain.com/sec/IF00.html". Is there a way that I can pull out just the short href as put in the anchor <a> tag? Or do I lose that by natural HTML behavior?

I suppose I could use a string manipulation to do this, but it gets tricky because my local page may actually be "http://www.thecurrentdomain.com/somedir/somepath/sec/IF00.html", and my href field may or may not have a subdirectory in it (for ex href="page.html" vs. href="sub/page.html"), so I cannot always just remove every thing before the last slash.

You may wonder why I am requesting this, and it is because it will just make the page a lot cleaner. If it is not possible to get just the short href (as put in the anchor <a> tag), then I could probably just insert an extra field into the tag, like link="sec/IF00.html", but again, that would be a little messier.