I write write my php file

myphp.php:
<?php
require("includes/application_top.php");
?>

and when i load this file from js code
have an error
<br />
<b>Warning</b>: require(includes/application_top.php) [<a href='function.require'>function.require</a>]: failed to open stream: No such file or directory in <b>/var/www/zen-test/includes/modules/select_check_box_count.php</b> on line <b>4</b><br />
<br />
<b>Fatal error</b>: require() [<a href='function.require'>function.require</a>]: Failed opening required 'includes/application_top.php' (include_path='.:/usr/share/php:/usr/share/pear') in <b>/var/www/zen-test/includes/modules/select_check_box_count.php</b> on line <b>4</b><br />

who knows what the problem?