slyfx chalange 3a

Hvad er mit navn, er kørt lidt død i denne lille javascript.. Noget der vil hinte mig lidt?

<SCRIPT LANGUAGE='JavaScript'>
<!--
function speak() {
    var codenm = new String(document.codename.name.value);
    var i = 0;
    var len = codenm.length;
    var xor = 1;
    var sol = new Array(82, 113, 98, 100, 102, 78, 98, 111);
    var good = "Good to see you friend. Let's get on with this mission...";
    var bad = "I'm sorry, i dont recognise you. Goodbye.";
    var res = 1;
   
    if (len != 8) res = 0;
   
    for(i = 0; i < len; i++) {
        if (res) {
            if (sol[i] != (codenm.charCodeAt(i) - xor)) res = 0;

            if (xor)
                xor = -1;
            else
                xor = 1;
        }
    }
   
    if (res)
        res = good;
    else
        res = bad;
   
    alert(res);
}
-->
</script>
Hello Agent Astro, please enter the codename : <br>
<form name=codename>
<input type=text name=name value=''>
<input type=button onClick=speak() value="Enter Name">
</form>