问div上的jQuery hide()和show()不起作用

EN

#loading {
    background: url('/img/loading.gif') no-repeat;
    width: 30px;
    height: 30px;
}

<button id="submit" type="submit" disabled>Submit</button>
<div id="loading" style="display:none"></div>

$(document).ready(function () {
  document.getElementById('submit').disabled = false; // enable the button

  $('#submit').click(function () {
        $(this).removeClass("active"); // either $(this) or $('submit')
        $(this).hide(); // either $(this) or $('submit')
        $('#loading').show();
  });
});