회원가입할때 생년월일 선택하는 셀럭트박스

간단한 소스라 모두들 다 아시겠지만 혹시나 모르시는 분을 위해서...........

<script language="javascript">
<!--
var today = new Date();
var toyear = parseInt(today.getYear());
var start = toyear - 5
var end = toyear - 70;

document.write("<font size=2><select name=birth1>");
document.write("<option value='' selected>");
for (i=start;i>=end;i--) document.write("<option>"+i);
document.write("</select>년  ");

document.write("<select name=birth2>");
document.write("<option value='' selected>");
for (i=1;i<=12;i++) document.write("<option>"+i);
document.write("</select>월  ");

document.write("<select name=birth3>");
document.write("<option value='' selected>");
for (i=1;i<=31;i++) document.write("<option>"+i);
document.write("</select>일  </font>");
//-->
</script>