401.vm 449 Bytes
<script>
    var currentUrl = this.location.href;
    function getQueryString(name) {
        var reg = new RegExp("(^|&)" + name + "=([^&]*)(&|$)", "i");
        var r = window.location.search.substr(1).match(reg);
        if (r != null) return unescape(r[2]);
        return null;
    }
    var param = getQueryString("returnUrl");
    //console.log(param);
    window.location="$config.getAuthUrl("index.htm")" + "?returnUrl=" + param ;
</script>