Find content in containers

find_content.js

var lookup = 'http://www.bbc.co.uk/programmes/p00fys8v';

var i=0;
var c=0;
var containers = db.content.find({lookup: lookup});
var found = null;

for (c=0; c<containers.length(); c++) {
    var container = containers[c];
    print("Currently processing "+container._id);
    for (i=0; i<container.contents.length; i++) {
        if (container.contents[i] != null && container.contents[i]._id == lookup) {
            print("Found "+container.contents[i]._id);
            found = container.contents[i];
        }
    }
}