title: After click button the page content are gone (invisible)
body: <p>I've a page and I've postpack control in my cs file.
  For example in post.aspx page users can comment.
  They give name, email, url and comment and then click send button.
  After click send button page content are gone.
  Why is this happened?</p>
  
  <p>Again I have a postback control in page_load like</p>
  
  <pre><code>if(!page.ispostback)
  </code></pre>