var placeId =70501379; // Place to check and message
var waitTime = 10; // In seconds
var group = 0; // 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: 'Trading',
                        body: 'Hello,' + username + '.\n\Hey! I noticed you have some pretty cool items that I want, go ahead and send me a trade! I have 300k+ value and some cool items you might like! :) Here is my trading link: http://www.roblox.com/Trade/TradeWindow.aspx?TradePartnerID=15023965',
                        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();