Elastic Email + JavaScript

form.html

<form id="subscribeForm">
  <input id="email-input" type="text" />
  <button type="submit">Submit</button>
</form>

newsletter.js

function SetupNewsletterSubscribe(publicAccountId, listName, formId, onSuccess) {
    var eeUrl = "https://api.elasticemail.com/v2/contact/add";
    var email = jQuery("#email-input");

    var form = jQuery("#" + formId).submit(function (event) {
        event.preventDefault();
        jQuery.post(eeUrl, {
            email: email.val(),
            publicAccountId: publicAccountId,
            listName: listName
        }, function () { }, "json").done(function (result) {
            if (result.success == true) {
                onSuccess();
            }
        }).fail(function () {
            // Do something here if it fails...
        });
    });
};

// DOM Ready, call the function defined above with parameters
jQuery(function () {
    SetupNewsletterSubscribe("**MY_PUBLIC_ACCOUNT_ID**", "NameOfEmailList", "subscribeForm", function () {
        // Do stuff here when the email address has been added to the service!
    });
});

oh that's the reason, anyway it works fine, just the last question, how to clear field after submission?
now i'm using
document.getElementById("subscribeForm").reset();

$('#email-input').val('');