title: how to create a knockout hint text custom binding?
body: <p>Im trying to create a custom binding to show hint texts in text inputs.</p>
  
  <p>so far I have this but it doesnt work:</p>
  
  <pre><code>ko.bindingHandlers.hintText= {
      init: function (element, valueAccessor) {
          element.focus(function () {
              if ($(this).val() === defaultText) {
                  $(this).attr("value", "");
              }
          });
          element.blur(function () {
              if ($(this).val() === '') {
                  $(this).val(valueAccessor());
              }
          });
      }
  }
  </code></pre>
  
  <p>the html:</p>
  
  <pre><code>&lt;input id="profileID" type="text" data-bind="hintText:'Enter Profile ID'" /&gt;
  </code></pre>