Dropdown field populated by Javascript (Not functioning with Firefox)

[fototex]

Hi Webmasters,

I have a Javascript on my credit card page which populates the elements of a dropdown field (The Year field).
It just works with Internet Explorer and not Firefox.

Here is the script:

<script type="text/javascript">
<%
Dim orderDateYearx
orderDateYearx = cStr(Year(Date))
%>

yy="<%=orderDateYearx%>";
yyyy=parseInt(yy);
yyyy=yyyy

var listDocUpload = document.getElementById("expDate2");
var optn = document.createElement("OPTION");
optn.value = yyyy;
yyyy=yyyy+""
optn.text = yyyy.replace("20","");
listDocUpload.options.add(optn);

yyyy=parseInt(yyyy)+1
var optn2 = document.createElement("OPTION");
optn2.value = yyyy;
yyyy=yyyy+""
optn2.text = yyyy.replace("20","");
listDocUpload.options.add(optn2);

yyyy=parseInt(yyyy)+1
var optn3 = document.createElement("OPTION");
optn3.value = yyyy;
yyyy=yyyy+""
optn3.text = yyyy.replace("20","");
listDocUpload.options.add(optn3);
</script>

The dropdown field in Firefox is just blank. I mean no elements reside within it. (but its clickable)

Any ideas why this dropdown field in Firefox is not going to be populated?
Thank you for all the comments.

[astupidname]

It probably has to do with how you are adding the option elements to the select. The 'add' method is by standard a member of the select object, plus the add method is treated differently in IE. Try using this function:

function addOption(select,option) {
    try {
        select.add(option,null); //standard method
    } catch(er) {
        select.add(option); //IE only
    }
}

Like so:

var optn = new Option(yyyy.replace('20', ''), yyyy);
addOption(listDocUpload, optn);
//etc... repeat for others

[daveVk]

replace lines like this
listDocUpload.options.add(optn);
with
listDocUpload.options[listDocUpload.options.length]=optn;

[fototex]

Hi all,

It did work after I have added an ID to the select.

Thank you again for all the responses.