json loop

var json = [{
    "id" : "1", 
    "msg"   : "hi",
    "tid" : "2013-05-05 23:35",
    "fromWho": "hello1@email.se"
},
{
    "id" : "2", 
    "msg"   : "there",
    "tid" : "2013-05-05 23:45",
    "fromWho": "hello2@email.se"
}];

You can loop over the Array like this:

for(var i = 0; i < json.length; i++) {
    var obj = json[i];

    console.log(obj.id);
}