PHP Code for Arduino Checkins

<?php
$checkin = stripslashes($_POST["checkin"]);
$val = json_decode($checkin);

$firstname = $val->user->firstName;
$lastname = $val->user->lastName;

$display = $firstname . " " . $lastname . " just checked in! Welcome, " . $firstname . "!";
$display = urlencode($display);

// I'm using +++ to indicate the start of the string and &&& to indicate the end for now
// I plan on writing Arduino code to interpret GET parameters so that it can be more
// easily ported for other uses.

$url = "http://ARDUINO_ADDRESS_HERE/+++" . $display . "&&&";

$str = file_get_contents($url);
$myFile = "logFile.txt";
$fh = fopen($myFile, 'a');
$checkin .= "\n\n";
fwrite($fh, $checkin);
fclose($fh);

echo "OK";
?>