PHP Decode

<?php  
  
goto rjJoj;  
l5p8t:  
$variable = str_replace("challengefox", '', $variable);  
goto MGxdQ;  
lIReG:  
function echec()  
{  
goto jCY0w;  
Dm3Uc:  
source();  
goto pj4hI;  
jCY0w:  
echo "Echec. <br />";  
goto Dm3Uc;  
pj4hI:  
exit;  
goto gPDe0;  
gPDe0:  
}  
goto lbiZM;  
bOncl:  
if ($variable === "challengefox") {  
echo "- Si ce texte apparait, tu valide la premiere etape! <br>"  
if (isset($_GET["challenge_fox"])) {  
echo "- Deuxieme etape valide! <br>";  
if (hash("md2", $_GET["variable2"]) == "0") {  
echo "- Troisieme etape valide! <br>";  
if (hash("sha1", $_GET["variable3"]) == $_GET["variable3"]) {  
echo "- Okay, voici le flag : " . $secretflag . "<br>";  
}  
}  
}  
}  
goto nKESF;  
HVY3V:  
echo "<p>Analyser le code ci dessous et trouver le moyen d afficher le flag.<p>";  
goto g9hQi;  
lbiZM:  
$variable = $_GET["variable"];  
goto l5p8t;  
Oz2JG:  
echo "<title>Challenge Fox</title>";  
goto E0h5E;  
MGxdQ:  
$query = urldecode($_SERVER["QUERY_STRING"]);  
goto Z_G58;  
MYfqC:  
function source()  
{  
goto nUBkJ;  
pqZ02:  
highlight_string(file_get_contents(__FILE__));  
goto P9KZ3;  
nUBkJ:  
echo "<br><code>";  
goto pqZ02;  
P9KZ3:  
echo "</code>";  
goto NTzIV;  
NTzIV:  
}  
goto lIReG;  
E0h5E:  
echo "<b>Challenge Fox</b>";  
goto HVY3V;  
Z_G58:  
if (preg_match("/ |_/", $query)) {  
echec();  
}  
goto bOncl;  
g9hQi:  
echo "<br><HR><br>";  
goto MYfqC;  
rjJoj:  
include "flag.php";  
goto Oz2JG;  
nKESF:  
source();  ?>