title: Calling jquery alert using ScriptManager in Asp.net
body: <p>I have a single line code that displays JS alert right now. I am trying to replace it with the jQuery alert so that I can theme it. Below is the code that I wrote for jQuery alert:</p>
  
  <pre><code>ScriptManager.RegisterStartupScript(this, GetType(), "onload", 
     "window.onload = function () {jAlert('This is a custom alert box', 'Alert Dialog');}", true); 
  </code></pre>
  
  <p>This code used to be like this:</p>
  
  <pre><code>ScriptManager.RegisterStartupScript(this, GetType(), "showalert", 
      "alert('This is a custom alert box');", true);
  </code></pre>
  
  <p>The existing code works fine. But my code gives me an error saying, </p>
  
  <p><code>value of property jalert is null</code></p>
  
  <p>I am unsure, what I am missing here.</p>