Fixed javascript

<html>
<head>
<script type="text/javascript">
<![CDATA[
function alertbox() {
    var name = prompt("Input your name please","")
    if(name != null && name != "") {
        alert("Thanks")
    }
    else if(name == null) {
        var doCancel = confirm("You are about to cancel this.\n" +
                               "Press ok to continue, or press cancel to go " +
                               "back and input your name!")
        if (!doCancel) {
            alertbox()
        }
    }
    else if(name == "") {
        alert("Please put a name in the text field!")
        alertbox()
    }
}
]]>
</script>
</head>
<body>
    <input type="button" onclick="alertbox()" value="Press Me!" />
</body>
</html>