Javscript Error in mxAjax implementation

[scooterSST]

Hey all,

This is my first foray into mxajax, I have it installed properly (I
think), however I'm getting the following error:
output from firebug:

element has no properties
_observeAndCache(undefined, "click", function(), false)prototype.js
(line 1966)
observe(undefined, "click", function(), false)prototype.js (line
1993)
setListeners()mxUpdateField.js (line 23)
initialize(Object executeOnLoad=false parser=Object
paramArgs=Object)mxUpdateField.js (line 5)
create()prototype.js (line 20)
init()detail.cfm (line 21)
onload(load )

[Break on this error]
if (element.addEventListener) { prototype.js (line 1966)

here's my code:

<script type='text/javascript' src='mxAjax/core/js/prototype.js?
jsVersion=#request.jsVersion#'></script>
<script type='text/javascript' src='mxAjax/core/js/mxAjax.js?
jsVersion=#request.jsVersion#'></script>
<script type='text/javascript' src='mxAjax/core/js/mxUpdateField.js?
jsVersion=#request.jsVersion#'></script>
<script language="javascript">
var url = "<cfoutput>#request.ajaxUrl#</cfoutput>";

function init() {
new mxAjax.UpdateField({
executeOnLoad:false,
parser: new mxAjax.CFArrayToJSArray(),
paramArgs: new mxAjax.Param(url,
{param:"empID={empID},statusID={statusID},contactMe={contactMe},statusNotes={statusNotes}",
cffunction:"fn_updateTTACStatus"}),
target: "statusID,contactMe,statusNotes",
source: "statusID,contactMe,statusNotes",
action: "go"
});
}


//addOnLoadEvent(function() {init();}); </script>

<input type="hidden" name="empID" id="empID"
value="<cfoutput>#IndvData.Id#</cfoutput>"/>
Status
<select name="statusID" id="statusID">
<option value="null">Select</option>
<cfoutput query="StatusDrop">
<option value="#ID#" <cfif IndvData.status eq
StatusDrop.ID>selected<cfelse></cfif>>#CodeDesc#</option>
</cfoutput>
</select>
<br />
Contact me here:
<input type="text" name="contactMe" id="contactMe"/>
<p></p>
Notes:
<textarea name="statusNotes" id="statusNotes" cols="45"
rows="5"></textarea> <br/>
<input name="go" type="button" value="go" />

any ideas?