AJAX :: Populate The Third Input In The Same Row As The Second Input Based Upon A Separate Db Query?

I've got a form in which the fields are being dynamically generated based upon a db query.. it looks something like this:

Code:

<form name="bft">
<input name="colA_1"> <input name="colB_1" onBlur="loadXMLDoc(this.value,'colC_1');"><input name="colC_1">

[code]...

I'm trying to use AJaX to populate the third input in the same row as the second input based upon a separate db query. Here's the code for that:

Code:

<script type="text/javascript">
function loadXMLDoc(v,n) {
if (window.XMLHttpRequest) {// code for IE7+, Firefox, Chrome, Opera, Safari

[code]...

Here's where it displays on the page<cfoutput>#trim(getITRRSP.[columnName])#</cfoutput>
Whenever the focus blurs from those inputs, the third column in that row is populated with "UNKNOWN" as the value. I have confirmed that the getITRRSP.cfm file is properly retrieving and displaying the data from the db query.