function validContact(formobj, fieldRequired, fieldDescription, msg){

	// intro des messages de la boite de dialogue
	var alertMsg = msg+" :\n";

	var l_Msg = alertMsg.length;

	for (var i = 0; i <= fieldRequired.length; i++){
		var obj = formobj.elements[fieldRequired[i]];
		if (obj){
			switch(obj.type){
			case "select-one":
				if (obj.selectedIndex == -1 || obj.options[obj.selectedIndex].text == "" || obj.options[obj.selectedIndex].value == "rien"){
					alertMsg += " - " + fieldDescription[i] + "\n";
				}
				break;
			case "select-multiple":
				if (obj.selectedIndex == -1){
					alertMsg += " - " + fieldDescription[i] + "\n";
				}
				break;

			case "checkbox":
					alert(obj.checked);
					if (obj.checked == false){
						alertMsg += " - " + fieldDescription[i] + "\n";
					}
					break;

			case "text":
			case "textarea":
				if (obj.value == "" || obj.value == null){
					alertMsg += " - " + fieldDescription[i] + "\n";
					/*obj.className = "contactErreur";*/
				}else{
					/*obj.className = "contact";*/
				}
				break;
			default:
				if (obj.value == "" || obj.value == null){
					alertMsg += " - " + fieldDescription[i] + "\n";
				}
			}
		}
	}

	var field = formobj.elements["mail"];
	if(field.value != null && field.value != ""){
		if(!checkmail(field.value)){
			alertMsg += " - votre mail doit être correct\n";
		}
	}

	if (alertMsg.length != l_Msg){
		alert(alertMsg);
		return false;
	}else{
		return true;
	}
}


function checkmail(email) {
	var reg = /^[a-z0-9._-]+@[a-z0-9.-]{2,}[.][a-z]{2,4}$/
    return (reg.exec(email)!=null)
}