firebase - How to retrieve only new data? -

i'm trying create simple notification system site admin, , need send real-time messages every admin user. when use firebase loads old data on every page, , user see messages database. if set limit(1) user see last notification on every page reloading:

var eventslist = new firebase('https://*****-messages.firebaseio.com/');  eventslist.on('child_added', function(message) {     var message = message.val();     $.notification(message.message); }); 

how can load new messages, without old notification history?

this design, in real-time system there no concept of "latest" data because it's changing. however, if want display items added list after page has loaded, can following:

var newitems = false; var eventslist = new firebase('https://*****-messages.firebaseio.com/');  eventslist.on('child_added', function(message) {   if (!newitems) return;   var message = message.val();   $.notification(message.message); }); eventslist.once('value', function(messages) {   newitems = true; });