jQuery.validator.addMethod("valeurinitiale", function(value, element, params) { 
    return this.optional(element) || value.toLowerCase()!=params.toLowerCase(); 
}, jQuery.validator.format("Veuillez saisir le champ {0} ")); 

$('#recommanderAmi').validate({
    submitHandler: function(form) {
        // do other stuff for a valid form
        if ($(form).valid())
        {
            $(form).ajaxSubmit(function(responseText, statusText) {
                if (responseText!="")
                    alert('probleme'+responseText);
                else {
                    $(form).clearForm();
       
                    jQuery.facebox(function() {
                        jQuery.get('resultat.php', function(data) {
                            jQuery.facebox( data )
                        })
                    })
                }
            })
        }
    },
    rules: {

        monemail: {
            required: true,
            email:true,
            valeurinitiale:"veuillez entrer votre e-mail"
        },
        email: {
            required: true,
            email:true,
            valeurinitiale:"veuillez entrer l e-mail de votre ami"
        }
    }	
});