title: Disable submit button until all form inputs have data
body: <p>I'm trying to disable the submit button until all inputs have some data. Right now the button is disabled, but it stays disabled after all inputs are filled in. What am I doing wrong?  </p>
  
  <pre><code>$(document).ready(function (){
      validate();
      $('input').on('keyup', validate);
  });
  
  function validate(){
      if ($('input').val().length &gt; 0) {
          $("input[type=submit]").prop("disabled", false);
      } else {
          $("input[type=submit]").prop("disabled", true);
      }
  } 
  </code></pre>