Using the code in the above KB link results in this:
I replace your code, for your reference:
<form action="" method="post" id="mc-embedde-subscribe-form" name="mc-embedded-subscribe-form" class="validate" target="_blank" novalidate>
<input type="email" value="Email" name="EMAIL" class="required email" id="mce-EMAIL">
<div id="mce-responses" class="clear">
<div class="response" id="mce-error-response" style="display:none"></div>
<div class="response" id="mce-success-response" style="display:none"></div>
</div> <!-- real people should not fill this in and expect good things - do not remove this or risk form bit signups-->
<div style="position: absolute; left: -5000px;"><input type="text" name="b_b9f1db9e41f059c8c5178_e5d68cf66b" tabindex="-1" value=""></div>
<div class="clear"><input type="submit" value="I'M IN" name="subscribe" id="mc-embedded-subscribe"></div>
</form>