Yeah, javascript inside the body tags is the last thing to fire on a landing page. You can redirect with an html meta-tag in the head of the page, that might actually fly before the rest of the page loads, something like:
<meta http-equiv="REFRESH" content="0;url=http://www.the-domain-you-want-to-redirect-to.com">
The 0 before the url tells it how many seconds to wait before redirecting.