Use PHP to get the current web address without the filename

Sometimes I need to grab the current web path without the current file name in order to pass a string in an email. As an example the current default location is http://www.effectivewebdesigns.co.uk/index.php, but in the future it may be http://www.effectivewebdesigns.co.uk/index.html or http://www.effectivewebdesigns.co.uk/default.html so sometimes I need to future proof.

<?php
$webAddress = 'http://'.$_SERVER['SERVER_NAME'];
$webAddress .= $_SERVER['REQUEST_URI'];
$webAddress = substr($webAddress, 0, 0-(strlen(basename($_SERVER['REQUEST_URI']))));
echo $webAddress;
?>