title: How to use __doPostBack()
body: <p>I'm trying to create an asyncrhonous postback in ASP.NET using <code>__doPostBack()</code>, but I have no idea how to do it.  I want to use vanilla JavaScript.</p>
  
  <p>Something simple like a button click can cause the <code>__doPostBack()</code> event to fire.  I'm just trying to learn how the mechanism works.</p>