[Coldfusion] URGENT...SVP aidez moi!! pb avec un form

Bonjour a tous, j'ai un probleme avec un formulaire.
Je vs explique.....
Je crée un formulaire sur ma page accueil.cfm dans lequel se trouve le cfselect CHOIX_FORUM.
lorsque j'affiche les resultats de la requete, j'ai decidé de limiter a l'affichage a 15 enregistrements par pages. J'ai donc un systeme de pagination. seul probleme lorsque ke je veux consulter les enregistrement de la pages 2 (cad les enregistrements 16 a 30), l'application me renvoe le message d'erreur suivant :
[red] [size=4]Element CHOIX_FORUM is undefined in FORM[/size=4][/red]
je vs en prie, prenez le tps de lire le code, et de m'aider a resoudre mon probleme... MERCI MERCI MERCI MERCI A TOUS CEUX QUI POURRONT m'apporter le moindre coup de mains.... A bientot tout le monde


page accueil.cfm

<cfloop index="i" from="1" to="#arraylen(session.utilisateur.droits_forum)#">
<cfoutput>#session.utilisateur.droits_forum#</cfoutput>
</cfloop>

<cfform action="index.cfm" method="post">
<table border="3">
<tr bordercolor="#00CCCC">
<td colspan="2" bgcolor="#00FFCC">
<cfselect name="choix_forum">
<cfquery name="categ" datasource="forum">
SELECT CAT_Libelle, CAT_id
FROM CATEGORIE RIGHT JOIN ACCES ON CATEGORIE.CAT_id = ACCES.ACC_id_forum
WHERE (ACCES.ACC_id_forum=CATEGORIE.cat_id)
AND <cfloop index="i" from="1" to="#arraylen(session.utilisateur.droits_forum)#">
(ACCES.ACC_id_droits = #session.utilisateur.droits_forum#)
<cfif i neq #arraylen(session.utilisateur.droits_forum)#>
OR
</cfif>
</cfloop>
GROUP BY CAT_libelle, CAT_id
</cfquery>
<cfoutput query="categ">
<option value=#categ.cat_id#>
#categ.CAT_Libelle#
</option>
</cfoutput>
</cfselect>
</td>
</tr>
<tr>
<td><input type="submit" value="Valider"></td>
</tr>
</table>
</cfform>



page index.cfm

<cfif isdefined("form.choix_forum")>
<cfset session.forum.cat = #form.choix_forum#>
</cfif>

<cfset CurrentPage=GetFileFromPath(GetTemplatePath())>

<cfparam name="PageNum_message_post" default="1">

<cfoutput>
<cfquery name="message_post" datasource="forum">
SELECT LISTE.for_id, LISTE.for_objet, LISTE.for_message, LISTE.for_date, LISTE.Compte, FORUM.for_loginid
FROM Liste, FORUM
WHERE (liste.for_cat_id = #session.forum.cat#)
AND (LISTE.for_id = FORUM.for_id)
ORDER BY LISTE.for_date DESC
</cfquery>
</cfoutput>


[red]c'est ici ke commence le code pour la pagination[/red]

<cfset MaxRows_message_post=15>

<cfset StartRow_message_post= Min((PageNum_message_post-1) * MaxRows_message_post+1, Max(message_post.RecordCount,1))>

<cfset EndRow_message_post= Min(StartRow_message_post+MaxRows_message_post-1, message_post.RecordCount)>

<cfset TotalPages_message_post=Ceiling(message_post.RecordCount/MaxRows_message_post)>

<cfset QueryString_message_post = Iif(CGI.QUERY_STRING NEQ "", DE("&"&CGI.QUERY_STRING), DE(""))>

<cfset tempPos=ListContainsNoCase(QueryString_message_post,"PageNum_message_post=","&")>

<cfif tempPos NEQ 0>
<cfset QueryString_message_post=ListDeleteAt(QueryString_message_post,tempPos,"&")>
</cfif>


<table width="100%">
<tr>
<th width="50%">&nbsp;</th>
<th width="50%" align="center">Recherche par Mots Clefs</th>
</tr>
<tr>
<td align="center"><a href="add.cfm?id=0" target="_blank">Ajouter un nouveau Post</a></td>
<td align="center"><cfinclude template="collection_search_form.cfm"></td>
</tr>
</table>

<br><br>


<table border="3" cellpadding="5" bordercolor="#CCCCCC" >
<tr bgcolor="#CCCCCC" align="center">
<th width="20%">Auteur</th>
<th width="50%">Objet</th>
<th width="20%">Date</th>
<td width="10%">Nb de reponses</td>
</tr>
<cfoutput query="message_post" startrow="#StartRow_message_post#" maxrows="#MaxRows_message_post#">
<tr bgcolor="##00CCCC">
<td><a href="view.cfm?id=#for_id#"><center>#for_loginid#</center></td>
<td>#for_objet#</td>
<td><center>#dateformat(for_date,"dd/mm/yyyy")# #timeformat(for_date,"HH:mm")#</center></td>
<td><center>#compte#</center></td>
</tr>
</cfoutput>
</table>


[red]C'est ici ke commence le code pour la pagination[/red]

<table border="0" width="50%" align="center">
<cfoutput>
<tr>
<td width="23%" align="center">
<cfif PageNum_message_post GT 1>
<a href="#CurrentPage#?PageNum_message_post=1#QueryString_message_post#"> <img src="images/first.gif" alt="Premier" border="0"></a>
</cfif>
</td>
<td width="31%" align="center">
<cfif PageNum_message_post GT 1>
<a href="#CurrentPage#?PageNum_message_post=#Max(DecrementValue(PageNum_message_post),1)##QueryString_message_post#"> <img src="images/previous.gif" alt="Pr&eacute;c&eacute;dent" border="0">
</a>
</cfif>
</td>
<td width="23%" align="center">
<cfif PageNum_message_post LT TotalPages_message_post>
<a href="#CurrentPage#?PageNum_message_post=#Min(IncrementValue(PageNum_message_post),TotalPages_message_post)##QueryString_message_post#"><img src="images/next.gif" alt="Suivant" border="0">
</a>
</cfif>
</td>
<td width="23%" align="center">
<cfif PageNum_message_post LT TotalPages_message_post>
<a href="#CurrentPage#?PageNum_message_post=#TotalPages_message_post##QueryString_message_post#"><img src="images/last.gif" alt="Dernier" border="0">
</a>
</cfif>
</td>
</tr>
</cfoutput>
</table>