SQL Update Dynamic form Names

Hello all,

Using CFloop updating SQL table with two or more records.

This page prints user subscriber bill.

GUI;

CFOUTPUT QUERY="PT"

A HREF="PtDemo.cfm?bill_id=#PT.bill_id#" target="_self">#subscriber#

td align="center">#ptnum# 
td align="center">#re#
td align="center"><font color="##FF0000">#phone#</font>

<cfset ptamount = 0>

<td align="center" >$ <font color="##ff0000">#ptamount#</font>  </td>

<td align="center">#psdate# align="center">#peDate#

<font color="##FF0000">#TV#</font>
$ <font color="##ff0000">#ttamount#</font>  

THE AMMOUNT FIELD BELOW IS THE FIELD IN NEED TO UPDATE IN SQL
input type="text" name="amount" value="#tBilledAmount# "

input type="Checkbox" name="bill" value="#bill_id#"

</CFOUTPUT>

PROCESSING FORM

<cfset pdate = dateformat(now(), "mm/dd/yyyy")>

cfset billedVar = "Y">
cfif isdefined("form.bill")>
cfoutput

CFLOOP INDEX="isid" LIST="#form.bill#"

<cfquery name="prcPna" datasource="wCast">

update billing

set billed = 'Y', billed_date = '#pdate#', amount = '#form.amount#', paid = 'y', paid_date = '#pdate#'

where bill_id = #bill_id#


</cfquery>


<!--- <cfoutput>#form.bill#</cfoutput> amount = '#form.ptnum#',--->
</CFLOOP>

</cfoutput>
</cfif>

Using the loop List, I can update the table with field names the are constant.

I need to update the calculated amount with ;
input type="text" name="amount" value="#tBilledAmount# " This will create a list; (#tBilledAmount# ex: "10,11,12")
OR
input type="text" name="#amount#" value="#tBilledAmount# " This will display "unknown field name"

Any ideas will help.

Thank you
T Jones