arguments.callee
<script type="text/javascript">
function fatorial (n) {
if(n == 0) {return 1};
return n*arguments.callee(n-1);
};
<script>
<body> <button type="button" onclick="alert(fatorial(5))">fatorial(5)</button> <button type="button" onclick="alert(fatorial(30)">fatorial(30)</button> <button type="button" onclick="alert(fatorial(456)">fatorial(456)</button> ...