Fatal error on link

Ok, so I installed and did everything fine [I think] with my site and wp. However, if you view my site here: http://worldofxtreme.net/ , everything looks fine. But when you click a link ex: http://worldofxtreme.net/info.php , where the latest article headlines are suppose to be scrolling up it says “fatal error” Here’s what it says to be exact:

Fatal error: Call to undefined function: get_archives() in /home/worldofx/public_html/wp-content/themes/Xtreme-01/header.php on line 73

Any ideas why this is happening? Thanks for any help!