function verif_form()
{
	var check_return=1;
	var message = "il manque qqlchose \n" ;
	if(document.getElementById('nom').value=="")
	{
		message += "le nom \n";
		document.getElementById('nom_erreur').style.display = "block";
		check_return = 0;
	}
	if(document.getElementById('prenom').value=="")
	{
		message += "le prenom \n";
		document.getElementById('prenom_erreur').style.display = "block";
		check_return = 0;
	}
	if(document.getElementById('tel').value=="")
	{
		message += "le tel \n";
		document.getElementById('tel_erreur').style.display = "block";
		check_return = 0;
	}
	if(document.getElementById('ad_mail').value=="")
	{
		message += "le e-mail \n";
		document.getElementById('mail_erreur').style.display = "block";
		check_return = 0;
	}
		else
		{
		a_pos =  document.getElementById('ad_mail').value.indexOf("@");
		dot_pos = document.getElementById('ad_mail').value.lastIndexOf(".");
		last_pos = document.getElementById('ad_mail').value.lenght-1;
		//alert ('position @ =' + a_pos + '\n' +'positiondu point =' + dot_pos);
		if(a_pos < 1 || dot_pos - a_pos <= 2 || last_pos - dot_pos >3 || last_pos + dot_pos > 2)
		{
		alert('email non valid');
		}
	}
	if(check_return == 0)
	{
	return false;
	}
}











function valid1()
{
	if(document.getElementById('prenom').value=="")
	{
		document.getElementById('prenom_erreur').style.display = "block";
	}
	if(document.getElementById('prenom').value!="")
	{
		document.getElementById('prenom_erreur').style.display="none";
	}

}



function valid2()
{
	if(document.getElementById('nom').value=="")
	{
		document.getElementById('nom_erreur').style.display = "block";
	}
	if(document.getElementById('nom').value!="")
	{
		document.getElementById('nom_erreur').style.display="none";
	}

}

function valid3()
{
	if(document.getElementById('tel').value=="")
	{
		document.getElementById('tel_erreur').style.display = "block";
	}
	if(document.getElementById('tel').value!="")
	{
		document.getElementById('tel_erreur').style.display="none";
	}

}


function valid4()
{
	if(document.getElementById('ad_mail').value=="")
	{
		document.getElementById('mail_erreur').style.display = "block";
	}
	if(document.getElementById('mail_erreur').value!="")
	{
		document.getElementById('tel_erreur').style.display="none";
	}

}