Callback
1. Alter the voting link for your site by adding /USER at end like:
http://rsps100.com/vote/YOURSERVERID/USER

YOURSERVERID (part already included in voting code).
USER is the account identifier for your player. It can be numbers, letters and underscore only.

2. Create your own postback.php PHP/MYSQL script. See example below.
3. Enter your Callback URL on Edit Server.

Only in case of a valid vote we send response with parameters USER to your defined Callback URL like:

http://yourdomain/callback.php?user=USER

Custom callback.php

define("TEST", 0); //set to 1 to make logs
define("LOG_FILE", "voting.log"); //if TEST is 1 will create this file as logs
$user = preg_replace('/[^A-Za-z0-9_]{1,64}/','',trim($_GET['user'])); //clean USER 1 to 64 letters, numbers and _
if(!$user || empty($user))
{
	if(TEST == true) {	
		error_log(date('[Y-m-d H:i] '). "[Invalid USER] No USER or invalid." . PHP_EOL, 3, LOG_FILE);
	}
}
else
{
	//Connect to DB
	$user = mysql_escape_string($user); //prevent SQL injection 
	//(1) check if $user exists 
	//(2) check if $user voted in last 12 hours
	//(3) insert new record, user vote + time
	//(4) run query to give reward to $user
	//Close DB connection
		
	if(TEST == true) {	
		error_log(date('[Y-m-d H:i] '). "[OK] Vote from USER: $user" . PHP_EOL, 3, LOG_FILE);
	}
}