Is your redirect conditional (i.e. does it only happen under certain circumstances, or does it always happen, no matter what)?
As-is, it seems to be an "every time" thing - in which case, you really don't need javascript to do it.
<meta http-equiv="Refresh" content="3;url=http://localhost/lookupsplashtest.php">
or, better yet, have your server send the HTTP header (php example):
header( 'Refresh: 3;url=http://localhost/lookupsplashtest.php' );