Probleme menus déroulants !

Bonjour,


Je vous explique mon problème, en fait j'ai 4 menus déroulants, je souhaite interagir le 1er avec le 2ème, et le 3ème avec le 4ème.

Le problème c'est que j'ai deux fonctions javascript, alors lorsque j'en utilise qu'une mon menu déroulant interagit correctement avec le 2eme.

voila comment ça se présente :

function choix(formulaire)
{

var j;
var i = formulaire.boite1.selectedIndex;
if (i == 0)
for(j = 1; j <18; j++)
formulaire.boite2.options[j].text="";


else{
switch (i){
case 1 : var text = new Array("Aide à la mise en service","Contrôle du matériel","Autre.","","","","","","","","","","","","","","","");
break;
case 2 : var text = new Array("Conseils de montage","Contrôle du matériel","Maintenance","Métrologie","Autre.","","","","","","","","","","","","","");
break;
case 3 : var text = new Array("Aide à la mise en service","Amélioration capteur","Amélioration","Bug software","Certificats","Conseils de montage","Contrôle du matériel","Critères d'exclusion","Informations générales","Maintenance","Métrologie","Mise à jour","Pannes","Présentation Produit","Problème Qualité","Sécurité","Test","Autre.");
break;
case 4 : var text = new Array("Aide à la mise en service","Contrôle du matériel","Informations générales","Maintenance","Autre.","","","","","","","","","","","","","");
break;
case 5 : var text = new Array("Aide à la mise en service","Contrôle du matériel","Informations générales","Maintenance","Métrologie","Présentation Produit","Test","Autre.","","","","","","","","","","");
break;
case 6 : var text = new Array("Aide à la mise en service","Amélioration","Certificats","Conseils de montage","Contrôle du matériel","Informations générales","Maintenance","Métrologie","Mise à jour","Pannes","Présentation Produit","Sécurité","Autre.","","","","","");
break;
case 7 : var text = new Array("Aide à la mise en service","Certificats","Informations générales","Maintenance","Mise à jour","Test","Autre.","","","","","","","","","","","");
break;
case 8 : var text = new Array("A définir","A définir","A définir","A définir","A définir","A définir","A définir","A définir","A définir","A définir","A définir","A définir","A définir","A définir","A définir","A définir","A définir","A définir","A définir");
break;
case 9 : var text = new Array("Informations générales","Métrologie","Autre.","","","","","","","","","","","","","","","");
break;
case 10 : var text = new Array("Consignes de sécurité","Divers","Plans de prévention","Règlement intérieur","Autre.","","","","","","","","","","","","","");
break;

}

for(j = 0; j<18; j++)
formulaire.boite2.options[j+1].text=text[j];
}
formulaire.boite2.selectedIndex=0;


}

function choix(formulaire2)
{
var y;
var x = formulaire2.boite3.selectedIndex;
if (x == 0)
for(y = 1; y <18; y++)
formulaire.boite4.options[y].text="";


else{
switch (x){
case 1 : var text = new Array("Analyseur","Chlore","Conductivité","Nitrate","Oxygène dissous","pH-Redox","Turbidité","","","","","","","","");
break;
case 2 : var text = new Array("Bus de terrain","Généralités","Interface","Passerelle","Protocole","","","","","","","","","","");
break;
case 3 : var text = new Array("Alimentation","Barrière","Calculateur","Contacteur","Convertisseur","Indicateur","","","","","","","","","");
break;
case 4 : var text = new Array("Bulle à bulle","Calculateur","Canal ouvert","Electromagnétiques","Massiques","Simulateurs","Thermiques","Ultrasons","Vortex","","","","","","");
break;
case 5 : var text = new Array("papier","sans papier","","","","","","","","","","","","","");
break;
case 6 : var text = new Array("","","","","","","","","","","","","","","");
break;
case 7 : var text = new Array("Applicator","Commuwin II","ControlCare Application Designer","FieldCare","FieldGate Viewer","FieldTool","FielTool","FMPDT","PDM","Prospy","ReadexT","Readwin","Readwin 2000","Service Tool","ToF Tool");
break;
case 8 : var text = new Array("Barrières Micro-ondes","Capacitif","Conductif","Gamma","Lames vibrantes","Micro-ondes","Palpeur mécanique","Ultrasons","","","","","","","");
break;
case 9 : var text = new Array("Asp-port","Asp-station","Asp 2000","Asp 9461D / 9465D","Asp Inline","Liqui-box","Liqui-compact","Liqui-port 2000","Station CE","","","","","","");
break;
case 10 : var text = new Array("Absolue / Relative","Différentielle","Hydrostatique","","","","","","","","","","","","");
break;
case 10 : var text = new Array("iTEMP","Omnigrad","Sonde","Transmetteur","","","","","","","","","","","");
break;

}

for(y = 0; y<18; y++)
formulaire2.boite4.options[y+1].text=text[y];
}
formulaire2.boite4.selectedIndex=0;
}



Et mes menus dans le body :

<form name="formulaire">
<label for="typedocu">Type de document :</label>
<select name="boite1" onChange="choix(this.form)">
<option selected>Tous types de documents</option>
<option>Checklists</option>
<option>Procédures de maintenance</option>
<option>Services infos</option>
<option>Services manuals</option>
<option>Support de formation</option>
<option>Documentation spéciale</option>
<option>Logiciels techniques</option>
<option>Software matériel</option>
<option>Documents liés aux prestations</option>
<option>Documentation sécurité</option>
</select>

<br />
<br />

<label for="specificite">Spécificité :</label>
<select name="boite2">
<option selected>Toutes spécificités</option>
<option></option>
<option></option>
<option></option>
<option></option>
<option></option>
<option></option>
<option></option>
<option></option>
<option></option>
<option></option>
<option></option>
<option></option>
<option></option>
<option></option>
<option></option>
<option></option>
<option></option>
<option></option>
</select>
</form>






<form name="formulaire2">

<label for="Famprod">Famille de produit :</label>
<select name="boite3" onChange="choix(this.form)">
<option selected>Tous types de produits</option>
<option>Analyse</option>
<option>Communication</option>
<option>Composant/Système</option>
<option>Débit</option>
<option>Enregistreur</option>
<option>Généralités</option>
<option>Logiciel technique</option>
<option>Préleveur</option>
<option>Préssion</option>
<option>Température</option>
</select>

<br />
<br />

<label for="principemesure">Principe de mesure :</label>
<select name="boite4">
<option selected>Tous principes de mesure</option>
<option></option>
<option></option>
<option></option>
<option></option>
<option></option>
<option></option>
<option></option>
<option></option>
<option></option>
</select>
</form>








Pouvez vous m'aider SVP