On select of drop down, another drop down appears

I am working on the code below as I have a need to have a certain drop down to appear on select on a value in the drop down before.

The code below is the basic option, but for some reason, its not working, am I missing something as below is every bit of the code related to it, I havent added anything else in relation to it.

Its at the bottom:
http://www.whhazardreport.co.uk/manager_Admin/detail.php?ID=66


<select id = "opts" onchange = "showForm()">
<option value = "0">Select Option</option>
<option value = "1">Option 1</option>
<option value = "2">Option 2</option>
</select>

<div id = "f1" style="display:none">
<select id = "opts" onchange = "showForm()">
<option value = "0">Select Option</option>
<option value = "1">Option 5</option>
<option value = "2">Option 6</option>
</select>
</div>

<div id = "f2" style="display:none">
<select id = "opts" onchange = "showForm()">
<option value = "0">Select Option</option>
<option value = "1">Option 3</option>
<option value = "2">Option 4</option>
</select>
</div>

<script type = "text/javascript">
function showForm(){
var selopt = document.getElementById("opts").value;
if (selopt == 1) {
document.getElementById("f1").style.display="block";
document.getElementById("f2").style.display="none";
}
if (selopt == 2) {
document.getElementById("f2").style.display="block";
document.getElementById("f1").style.display="none";
}
}

</script>

The code seems fine, but its either not reading the value or the changing of the display value isnt working, but it seems to be fine.

OK have made a little progress by using document.write


<script type = "text/javascript">
function showForm(){
document.write('lee');

var selopt = document.getElementById("opts").value;
if (selopt == 1) {
document.write('lee1');
document.getElementById("f1").style.display="block";
document.getElementById("f2").style.display="none";
}
if (selopt == 2) {
document.write('lee2');
document.getElementById("f2").style.display="block";
document.getElementById("f1").style.display="none";
}
}
</script>

I can get lee to appear, but neither lee1 or lee2 works, so it knows called showForm, but the value isnt being read and so nothing is happening

Thank you, Ive sorted it out now.

Cheers