function VerificationEmail(elm)
{
if (elm.value.indexOf("@") != "-1" &&
    elm.value.indexOf(".") != "-1" &&
    elm.value != "")
    return true;

return false;
}

function VerificationFormulaire()
{

if (VerificationEmail(document.ajouter.user_email) == false)
    {
    alert("Email non Valide.");
    document.ajouter.user_email.focus();
    return false;
    }

return true;
}