var placeId = 9528010; // Place to check and message
var waitTime = 25; // In seconds
var group = 938940; // 0 for no group check, otherwise people in this group will not receive the message
function sendMsg(userId, username) {
        function send() {
                $.post("http://www.roblox.com/messages/send",{
                        subject: 'Join The Great Army of Britannia',
                        body: 'Hello, ' + username + '.\n\ Join The Great Army of Britannia, a highly active recreation of colonial British Army in the 1800s. We noticed that you are an extremely skilled fighter, and  we could use you in the line of duty. Enlist today! http://www.roblox.com/My/Groups.aspx?gid=938940 If you have any questions, feel free to contact me!',
                        recipientid: userId,
                        cacheBuster: new Date().getTime()
                }).done(function(response) {
                        if (response.success == true) {
                                console.log('Sent message to ' + username + ' (' + userId + ')');
                        } else {
                                console.log('Error sending to ' + username + ': ' + response.shortMessage);
                        }
                });
        }
        if (group > 0) {
                $.get("http://www.roblox.com/Game/LuaWebService/HandleSocialRequest.ashx?method=IsInGroup&playerid=" + userId + "&groupid=" + group, function(response) {
                        if(response.indexOf('true') == -1) {
                                send();
                        } else {
                                console.log('Didn\'t send a message to ' + username + ' because he is already in group ' + group + '.');
                        }
                });
        } else {
                send();
        }
}

var i=0;
function run() {
        var timeout = 0;
        var url = "http://www.roblox.com/games/getgameinstancesjson?placeId=" + placeId +"&startindex=" + i*10;
        $.get(url).done(function(obj){
                for (var server in obj.Collection) {
                        for (var players in obj.Collection[server].CurrentPlayers) {
                                var plr = obj.Collection[server].CurrentPlayers[players];
                                if (plr.Id > 0) {
                                        (function(time,id,name) {
                                                setTimeout(sendMsg,time,id,name);
                                        })(timeout,plr.Id,plr.Username);
                                        timeout+=waitTime*1000;
                                }
                        }
                }
                i++;
                setTimeout(run, timeout);
        });
}
run();