i have this script to enterhandler event for my form but i have problem.
why is it not working with some form elements like select and radio/checkbox?
how can we attained to accomplished that full function?
any help will appreciate thanks in advance..


<script>
function EnterHandler(oEvent){
//var oEvent = (navigator.appName == "Netscape")?
oNSEvent : event;
var oElm = (navigator.appName == "Netscape")?
oEvent.target : event.srcElement;
if(oEvent.keyCode == 13){
var intNewIndexFocus =
parseInt(oElm.getAttribute("indexNo"), 10) + 1;
var arrInputFields =
document.getElementById("myform").getElementsByTagName("input");
for(var i=0; i<arrInputFields.length; i++){
var oInput = arrInputFields[i];
if(oInput.getAttribute("type") == "text"
&& parseInt(oInput.getAttribute("indexNo"), 10) == intNewIndexFocus){
oInput.focus();
}
}
(navigator.appName == "Netscape")?
oEvent.preventDefault() : event.returnValue = false;
}
}
</script>
<form name="myform" method="POST" action="formvalidate.htm">Demo: Enter Key Event
<table bgcolor="#9ABEF4">
<tr>
<td class="formTxt">PoliticalID</td>
<td><input name="polID" type="text" size="13" indexNo="1" onKeyDown="EnterHandler(event)">&nbsp;
<a href="javascript:explain('Political ID', 'opener.document.myform.polID.value', 'The Political ID field is where you enter the unique number or ID for the purpose of indentification key access and to easily identify the politician person. .');" onMouseOver="window.status='Click for explanation...';return true;" onMouseOut="window.status='';return true;">Help?</a>
</td>
</tr>
<tr>
<td class="formTxt">Surname</td>
<td><input name="surname" type="text" size="50" indexNo="2" onKeyDown="EnterHandler(event)"></td>
</tr>
<tr>
<td class="formTxt">FirstName</td>
<td><input name="firstname" type="text" size="35" indexNo="3" onKeyDown="EnterHandler(event)"></td>
</tr>
<tr>
<td class="formTxt">BirthDate</td>
<td><input type="text" name="birthdate" size="16" indexNo="4" onKeyDown="EnterHandler(event)"><i>(mm/dd/yyyy)</i></td>
</tr>
<tr>
<td colspan="2">
<table cellspacing="3" cellpadding="0">
<tr>
<td>
<select size="1" name="inames0" indexNo="5" onKeyDown="EnterHandler(event)">
<option value="1" selected>---------- Province Names ----------</option>
<option value="something">ABRA</option>
<option value="something">BOHOL</option>
<option value="something">COTOBATO</option>
</select>
</td>
</tr>
<tr>
<td>
<select size="1" name="inames1" indexNo="6" onKeyDown="EnterHandler(event)">
<option value="1" selected>---------- Municipality Names ----------</option>
<option value="something">Aurora</option>
<option value="something">Antipolo City</option>
<option value="something">Pasay City</option>
</select>
</td>
</tr>
<tr>
<td>
<select size="1" name="inames2" indexNo="7" onKeyDown="EnterHandler(event)">
<option value="1" selected>---------- Barangay Names ----------</option>
<option value="something">Barangay 1</option>
<option value="something">Barangay 10</option>
<option value="something">Sitio Upo</option>
</select>
</td>
</tr>
</table>
</td>
</tr>
<tr>
<td colspan="2" align="center">
<p><input type="submit" value="Send" name="submit"></p>
</td>
</tr>
</table>
</form>