Flickr API JSONP

CSS

ul{
    list-style-type: none;
    background-color: #eee;
    border-radius: 10px;
    margin-bottom: 10px;
    padding: 10px;
}

JavaScript

var url = "http://api.flickr.com/services/rest/?method=flickr.photos.getSizes&format=json&api_key=708f179518b2093d23f0aef284b565a4&photo_id=6115633659&jsoncallback=?";
var largeSRC = "";
$.getJSON(url,{
per_page:50
}, function(data) {
    $.each(data.sizes.size, function(i, datum) {
        $.each(datum, function(key, value) {
            if (key === "label" && value === "Original") {
                largeSRC = datum.source;
                alert(largeSRC);
            }
        });
    });
});