I have a website and i want to add a feature post system in my website header. for example, i can tell you a website name (labnolDOTorg). i want to do like this website. he did this using PHP may be. can anyone help me in this matter?
The way I see it, this reminds me more of a blog than a post system. You can set up a wordpress blog in no time (http://wordpress.com/) whether you want it on your site or as a separate domain. The person administering the site probably had comments disabled and make a custom theme for the blog. If you really want to code such a system in PHP you would have to have the time and nerves to deal with PHP and MySQL, set up a database and think on how and what functionality you would want your "posting system" to have.
You can use any cms like the above (wordpress, joomla, drupal..) or find a php blog script to merge with your already built system.