Help with code

I got this code from another user, seems to work but has a minor problem.

It reads a query and produces line items on a form, using #currentrow#. I then pass the values to the action page to update, which is below :

<cfloop from="1" to="#form.record_count#" index="row">

<cfif isDefined("form.urdn_line_item#row#")>
<cfparam name="form.urdn_line_item#row#">
<cfelse>
<cflocation url="close_disposition_urdn_line_items.cfm?urdn_number=#urdn_number#&coming_from_error=radio_buttons">
</cfif>

<cfparam name="form.instructions#row#">
<cfparam name="form.tracking_number#row#">
<cfparam name="form.urdn_action#row#">
<cfparam name="form.urdn_line_item#row#">
<cfparam name="form.urdn_number#row#">


<cfset instructions = form["instructions"& row]>
<cfset tracking_number = form["tracking_number"& row]>
<cfset urdn_action = form["urdn_action"& row]>
<cfset urdn_line_item = form["urdn_line_item"& row]>
<cfset urdn_number = form["urdn_number"& row]>


<cfquery name="qryUpdate_urdn_line_items" datasource="recDisc">
update tblUnReceivables_urdn_line_items
set tracking_number = '#tracking_number#',
<cfif instructions is "">
instructions = 'None'
<cfelse>
instructions = '#instructions#'
</cfif>
where urdn_number = '#urdn_number#'
and urdn_line_item = '#urdn_line_item#'
and urdn_action = '#urdn_action#'
</cfquery>

</cfloop>

The problem that I am having is that if a value is 123456 and I try to update it with 99999, the value acutally becomes 123456,99999 in the sql table, instead of 99999 overriding 123456.

How do I correct this ?

Thanks