Someone tell me where I'm going wrong. I'm trying to print out the month/year ?

Code:
<html><head>
<SCRIPT language=JavaScript>
var dateNow = new Date();
var monthNow = dateNow.getMonth();
var yearNow = dateNow.getYear();
function MakeArray(n) {
this.length = n
return this
} 
monthNames = new MakeArray(12)
monthNames[1] = "Janurary"
monthNames[2] = "February"
monthNames[3] = "March"
monthNames[4] = "April"
monthNames[5] = "May"
monthNames[6] = "June"
monthNames[7] = "July"
monthNames[8] = "August"
monthNames[9] = "Sept."
monthNames[10] = "Oct."
monthNames[11] = "Nov."
monthNames[12] = "Dec."
function customDate(oneDate) {
var theMonth = monthNames[oneDate.getMonth() +1]
}
</SCRIPT>
</head><body><script type="text/javascript">
document.write(theMonth + "/" + yearNow);
</script>
</body></html>