Defaced Checker

<html>
<style type="text/css">
html {
    margin: 10px auto;
    text-align: center;
    background: #000000;
    color: #008000;
}
a {
    color: lime;
    text-decoration: none;
}
textarea, input {
    border: 1px solid #008000;
    color: #bb0000;
    background: transparent;
}
</style>
<form method="post">
Target: <br>
<textarea name="url" style="resize: none; margin: 5px auto; padding-left: 5px; width: 500px; height: 250px;" placeholder="http://target.com"></textarea><br>
<input type="submit" name="go" value="Hajar" style="margin: 5px auto; width: 250px; height: 20px;">
</form>
<?php
$url = explode("\r\n", $_POST['url']);
$go = $_POST['go'];
function ambil($target) {
    $ambil = htmlspecialchars(@file_get_contents($target));
    return preg_match("/IndoXploit/", $ambil); // ganti IndoXploit dengan kata-kata yang ada di scriptmu
}
if($go) {
    foreach($url as $sites) {
        if(ambil($sites)) {
            echo "<a href='$sites' target='_blank'>$sites</a><br>";
        }
    }
}
?>
</html>