Adding Numbers:

The Script:

<script type="text/javascript">
function add(){
var tot=0,a=arguments,b=a.length;
while(b--){
if(!a || isNaN(a[b]) || !a[b]){continue;}
tot+= +a[b];
}
return tot;
}
}
</script>

The example:

<script type="text/javascript">
alert(add(1,2,3,4,5));
</script>

Try it

More Maths.