<script src="https://cdn.staticfile.org/jquery/2.2.4/jquery.min.js"></script>

<div id='parent_div'>

    <div id='div_1'>1</div>

    <div id='div_2'>2</div>

    <div id='div_3'>3</div>

</div>

var e = $("#div_2");

// move up:

e.prev().insertAfter(e);

// move down:

//e.next().insertBefore(e);