title: Knockout - Event seems to fire on page load?
body: <p>I have a ViewModel which has a dropdown like so:</p>
  
  <pre><code>&lt;select data-bind="options: orderDropdown,
      value: selectedOrder, 
      optionsCaption: '---',
      event: { change: loadOrderDetails }"&gt;
  &lt;/select&gt;
  </code></pre>
  
  <p>Then the <code>loadOrderDetails</code> is set like this:</p>
  
  <pre><code>// loads details of selected order
  self.loadOrderDetails = function () {
      $.ajax({
          url: "/api/OrderDetails",
          data: { id: self.selectedOrder() },
          type: "GET",
          success: function (data) {
              self.orderDetails(data);
          }
      });
  }
  </code></pre>
  
  <p>The problem is, this event seems to fire when the page loads as when I look in the console I see this:</p>
  
  <p><code>GET http://localhost:52559/api/OrderDetails 400 (Bad Request)</code></p>
  
  <p>Any idea how I can prevent this from firing on page load?</p>