When checkbox is checked show hidden button and hide the visible button

I am a beginner in javascript, hopefully you can help me with this problem..

I have 2 buttons in html form and 1 checkbox, 1 button should be hidden and the other is visible. My problem is how to show the hidden button and hide the visible button at the same time when the checkbox is checked..

I know how to hide/show the button flip-ch1 but I can't do it to other button.

I have a script here:

$(document).ready(function() {
  $('#flip-ch1').hide();
  $('#radio').mouseup(function() {
    $('#flip-ch1').toggle();

  });
});

<script src="http://ift.tt/1oMJErh"></script>
<div>
  <input type="checkbox" name="radio" id="radio">

  <button class="btn_style" id="ch1">Add</button>
  <button class="btn_style" id="flip-ch1">Add</button>

</div>