function Verif()
{
    envoi=true;
    message="The following field has to be filled :\n";
    if(document.form.nom.value=="")
    {
        message=message+"Last Name\n";
        envoi=false;
    }
    
    if(document.form.prenom.value=="")
    {
        message=message+"First Name\n";
        envoi=false;
    }
    
    if(document.form.mail.value=="")
    {
        message=message+"E-Mail\n";
        envoi=false;
    }
	
	if(document.form.telephone.value=="")
    {
        message=message+"Telephone \n";
        envoi=false;
    }
    if(!envoi)
    {
        alert(message);
    }
    else
    {
        document.form.submit();
    }
        
}