lightbox modal window

i was hoping to utilize lightbox to create a modal window which in turn would display recent posts and comments. however, it seems as though the php file is not being recognized as being part of the wordpress loop. at the moment i’m have this loaded in a standalone php file:

<div id=”searchbox”><form method=”get” id=”searchform” action=”/wordpress/”>
<input type=”text” value=”” name=”s” id=”s” />
<input type=”submit” value=”Find” class=”submit” id=”searchbutton” value=”Search” />
</form></div>

<ul class=”recents”>
<?php get_archives(‘postbypost’, ’15’, ‘custom’, ‘

• ‘, ‘

‘); ?>

on activating the box, the search box functions as it should. unfortunately, i receive the following error message for get_archives:

Fatal error: Call to undefined function get_archives()

i’ve attempted to add the wp loop to the modal box but receive errors as well. ideas?

(this is all running on a local install)