//Contrôle du formulaire contact
function envoyer_message() {
	form = document.getElementById("formulaire_contact");
	
	//if(form.nom.value != "" && form.mail.value != "" && form.message.value != "" && controle_mail(form.mail.value) == true)
	//Controle mail ne focntionne pas avec les adresses dont le nom de domaine contient un tiret
	if(form.nom.value != "" && form.mail.value != "" && form.message.value != "" && form.societe.value != "")
	{ 
		return true;
	}
	else
	{
		alert("Merci de remplir les champs obligatoires.");
		return false;
	}
}

//change the opacity for different browsers
function changeOpac(opacity, id) {
	var object = document.getElementById(id).style; 
	object.opacity = (opacity / 100);
	object.MozOpacity = (opacity / 100);
	object.KhtmlOpacity = (opacity / 100);
	object.filter = "alpha(opacity=" + opacity + ")";
}

//Transition image de fond
function blendimage(divid, imageid, imagefile, millisec) {
	var speed = Math.round(millisec / 100);
	var timer = 0;
	
	//set the current image as background
	document.getElementById(divid).style.backgroundImage = "url(" + document.getElementById(imageid).src + ")";
	
	//make image transparent
	changeOpac(0, imageid);
	
	//make new image
	document.getElementById(imageid).src = imagefile;

	//fade in image
	for(i = 0; i <= 100; i++) {
		setTimeout("changeOpac(" + i + ",'" + imageid + "')",(timer * speed));
		timer++;
	}
}

function change_page(id_page) {
	
	var speed = 2;
	var timer = 0;
	var i = 0;
	
	//On cahge l'image de fond
	blendimage('div_fond','image_fond', './Images/' + id_page + '.gif',500);
	
	//on s'occupe du menu
	table_menu = document.getElementsByName("le_menu");
	for(i = 0; i < table_menu.length; i++)
	{
		table_menu[i].style.color = "#FFFFFF";
	}
	document.getElementById(id_page).style.color = "#FF0000";
	
	//on va chercher la page en ajax
	ajax('contenu_principal','doc=' + id_page);
	
}