title: The form code does not work in firefox (submit and alert)
body: <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-js lang-js prettyprint-override"><code>$(document).ready(function () {
    $("#submitButton").click(function () {
      $.post($("#payment").attr("action"), $("#payment").serialize(),
             function () {
        alert('Form 1 submitted');
      });
  
      $.post($("#normal").attr("action"), $("#normal").serialize(),
             function () {
        alert('Form 1 submitted');
      });
    });
  });</code></pre>
  <pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"&gt;&lt;/script&gt;
  &lt;form id="normal" action="send.php" method="post" enctype="multipart/form-data"&gt;
    &lt;input type="text" name="fio" placeholder="  (Имя получателя)" id="q" required="required"/&gt;&lt;br&gt;
    &lt;input type="text" name="country" placeholder="" id="w" required="required"/&gt;&lt;br&gt;
    &lt;input type="text" name="street" placeholder="  улица, дом, квартира" id="e" required="required"/&gt;&lt;br&gt;
    &lt;input type="text" name="bl" placeholder="  Квартира, блок и т.п. (при необходимости)" id="o"/&gt;&lt;br&gt;
    &lt;input type="text" name="city" placeholder="" id="r" required="required"/&gt;&lt;br&gt;
    &lt;input type="text" name="region" placeholder="" id="t" required="required"/&gt;&lt;br&gt;
    &lt;input type="number" name="index" placeholder="" id="y" required="required"/&gt;&lt;br&gt;
    &lt;input type="number" name="mobnumber" placeholder="  В международном формате" id="u" required="required"/&gt;&lt;br&gt;&lt;/form&gt;
  
  &lt;form id="payment" name="payment" method="post"    action="https://sci.interkassa.com/" enctype="utf-8"&gt;
    &lt;input type="hidden" name="ik_co_id" value="58515c6a3c1eafd5708b4569" /&gt;
    &lt;input type="hidden" name="ik_pm_no" value="ID_4233" /&gt;
    &lt;input type="hidden" name="ik_am" value="382" /&gt;
    &lt;input type="hidden" name="ik_cur" value="UAH" /&gt;
    &lt;input type="hidden" name="ik_desc" value="Event Description" /&gt;
    &lt;input type="hidden" name="ik_act" value="payways" /&gt;
    &lt;input type="hidden" name="ik_pw_off" value="yandexmoney" /&gt;
    &lt;input type="hidden" name="ik_suc_u" value="https://www.yandex.ua/" /&gt;
    &lt;input type="hidden" name="ik_fal_u" value="https://www.yandex.ua/" /&gt;
    &lt;input type="hidden" name="ik_pnd_u" value="https://www.yandex.ua/" /&gt;
    &lt;input type="hidden" name="ik_exp" value="2016-12-15" /&gt;
    &lt;input type="hidden" name="ik_ltm" value="3600" /&gt;
    &lt;input type="hidden" name="ik_loc" value="ru" /&gt;
    &lt;input type="hidden" name="ik_enc" value="utf-8" /&gt;
    &lt;input type="hidden" name="ik_int" value="web" /&gt;
    &lt;input type="hidden" name="ik_am_t" value="payway" /&gt;
    &lt;input type="submit" id="submitButton" value="ОПЛАТИТЬ" id="sub"/&gt;&lt;/form&gt;</code></pre>
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  </p>
  
  <p>This code works on all browsers except Firefox (forms sent successfully, the redirect works, the site asks for confirmation alert). But firefox immediately redirecting to the site without  send forms and confirm the alert. Help please, i dont found answer in ru internet. HELP ME PLEASE.
  P.S. Sorry for my english, I use GOOGLE translator, but I try to make the text readable. thank you in advance</p>