function verif_champs()
{

	nom=document.getElementById('nom').value;
	prenom=document.getElementById('prenom').value;
	email=document.getElementById('email').value;
	message=document.getElementById('message').value;
	if(nom == "")
	{
		alert("Veuillez entrer votre nom SVP");
		focus('nom');
		return false;
	}
	if(prenom== "")
	{
		alert("Veuillez entrer votre prenom SVP");
		focus();
		return false;
	}
			
	if(email.indexOf('@') == -1)
	{
		alert("Adresse Email invalide!");
		focus();
		return false;
	}
	if(email.length <7)
	{
		alert("Adresse Email invalide!");
		focus();
		return false;
	}
	if(message.length <7)
	{
		alert("veuillez insérer votre message");
		focus();
		return false;
	}
}

<!--
function MM_openBrWindow(theURL,winName,features) { //v2.0
  window.open(theURL,winName,features);
}
//-->
function change_photo(url_photo,nom_photo) {
			document.images[nom_photo].src="url_photo";					
		}

var delayb4scroll=2000 //Specify initial delay before marquee starts to scroll on page (2000=2 seconds)
var marqueespeed=2 //Specify marquee scroll speed (larger is faster 1-10)
var pauseit=1 //Pause marquee onMousever (0=no. 1=yes)?

////NO NEED TO EDIT BELOW THIS LINE////////////

var copyspeed=marqueespeed
var pausespeed=(pauseit==0)? copyspeed: 0
var actualheight=''

function scrollmarquee(){
if (parseInt(cross_marquee.style.top)>(actualheight*(-1)+8))
cross_marquee.style.top=parseInt(cross_marquee.style.top)-copyspeed+"px"
else
cross_marquee.style.top=parseInt(marqueeheight)+8+"px"
}

function initializemarquee(){
cross_marquee=document.getElementById("vmarquee")
cross_marquee.style.top=0
marqueeheight=document.getElementById("marqueecontainer").offsetHeight
actualheight=cross_marquee.offsetHeight
if (window.opera || navigator.userAgent.indexOf("Netscape/7")!=-1){ //if Opera or Netscape 7x, add scrollbars to scroll and exit
cross_marquee.style.height=marqueeheight+"px"
cross_marquee.style.overflow="scroll"
return
}
setTimeout('lefttime=setInterval("scrollmarquee()",30)', delayb4scroll)
}

if (window.addEventListener)
window.addEventListener("load", initializemarquee, false)
else if (window.attachEvent)
window.attachEvent("onload", initializemarquee)
else if (document.getElementById)
window.onload=initializemarquee