ajax form

// Look at the AJAX section
$('form.email-form').submit(function (e) {
        // return false so form submits through jQuery rather than reloading page.
        if(e.preventDefault) e.preventDefault();
        else e.returnValue = false;

        var thisForm        = $(this).closest('.email-form'),
            error           = 0,
            originalError   = thisForm.attr('original-error'),
            loadingSpinner;

        if (typeof originalError !== typeof undefined && originalError !== false) {
            thisForm.find('.form-error').text(originalError);
        }


        $(thisForm).find('.validate-required').each(function(){
            if($(this).val() === ''){
                $(this).addClass('field-error');
                error = 1;
            }else{
                $(this).removeClass('field-error');
            }
        });

        $(thisForm).find('.validate-email').each(function(){
            if(!(/(.+)@(.+){2,}\.(.+){2,}/.test($(this).val()))){
                $(this).addClass('field-error');
                error = 1;
            }else{
                $(this).removeClass('field-error');
            }
        });


        if (error === 1){
            $(this).closest('.email-form').find('.form-error').fadeIn(200);
        }else {
            // Hide the error if one was shown
            $(this).closest('.email-form').find('.form-error').fadeOut(200);
            // Create a new loading spinner while hiding the submit button.
            loadingSpinner = $('<div />').addClass('form-loading').insertAfter($(thisForm).find('input[type="submit"]'));
            $(thisForm).find('input[type="submit"]').hide();

            jQuery.ajax({
                type: "POST",
                url: "mail/mail.php",
                data: thisForm.serialize(),
                success: function (response) {
                    // Swiftmailer always sends back a number representing numner of emails sent.
                    // If this is numeric (not Swift Mailer error text) AND greater than 0 then show success message.
                    $(thisForm).find('.form-loading').remove();
                    $(thisForm).find('input[type="submit"]').show();
                    if($.isNumeric(response)){
                        if(parseInt(response) > 0){
                            thisForm.find('.form-success').fadeIn(1000);
                            thisForm.find('.form-error').fadeOut(1000);
                            setTimeout(function(){ thisForm.find('.form-success').fadeOut(500); }, 5000);
                        }
                    }
                    // If error text was returned, put the text in the .form-error div and show it.
                    else{
                        // Keep the current error text in a data attribute on the form
                        thisForm.find('.form-error').attr('original-error', thisForm.find('.form-error').text());
                        // Show the error with the returned error text.
                        thisForm.find('.form-error').text(response).fadeIn(1000);
                        thisForm.find('.form-success').fadeOut(1000);
                    }
                },
                error: function (errorObject, errorText, errorHTTP) {
                    // Keep the current error text in a data attribute on the form
                    thisForm.find('.form-error').attr('original-error', thisForm.find('.form-error').text());
                    // Show the error with the returned error text.
                    thisForm.find('.form-error').text(errorHTTP).fadeIn(1000);
                    thisForm.find('.form-success').fadeOut(1000);
                    $(thisForm).find('.form-loading').remove();
                    $(thisForm).find('input[type="submit"]').show();
                }
            });
        }
        return false;
    });