ok cest bon jai trouvé et ca marche en javascript:
<script>
function calcul () {
var val1=0;
var val2=0;
var val3=0;
if(document.caddie.select1.value != "select1")
val1=document.caddie.select1.value;
caddie.Total.value=val1;
if(document.caddie.select2.value != "select2){
val2=document.caddie.select2.value;
caddie.Total2.value=val2;
}
if(document.caddie.select3.value != "select3"){
val3=document.caddie.select3.value;
caddie.Total3.value=val3;
}
var totaux = val1 - val2 - val3;
caddie.totaux.value = totaux;
}
</script>
<body onload="calcul(this)">
<FORM name="caddie">
<SELECT name="select1" onchange="calcul(this)">
<OPTION SELECTED>select1
<OPTION VALUE="Potages">Potages
<OPTION VALUE="Entrée froides">Entrées
<OPTION VALUE="Entrées chaudes">Dessert
</SELECT>
<input type="text" name="Total" size="8" readonly>
<br>
<SELECT name="select2" onchange="calcul(this)">
<OPTION SELECTED>select2
<OPTION VALUE=1>Artichaud
<OPTION VALUE=2>Asperge
<OPTION VALUE=3>Auberge
</SELECT>
<input type="text" name="Total2" size="8" readonly>
<br>
<SELECT name="select3" onchange="calcul(this)">
<OPTION SELECTED>select3
<OPTION VALUE=1><b>Agneau</b>
<OPTION VALUE=2>Pavé
<OPTION VALUE=3>Côte
</SELECT>
<input type="text" name="Total3" size="8" readonly>
<br>
<br>Total:
<input type="text" name="totaux" value="1000" size="8" readonly>
</FORM>
</body>
bon ok mes calculs sont bidon mais dans le principe ca fonctionne
bon codage a tous