<?php

$jsonString = file_get_contents('php://input');

$data = json_decode($jsonString);

$dataString = $data->username.",".$data->color.",".$data->size."\n";

$filename = "welcomedata.txt";
$myfile = fopen($filename, "a");
if (!$myfile) {
   die("Unable to open $filename.");
}
fwrite($myfile, $dataString);
fclose($myfile);		
		
?>