callbackproblem.js

var item = { "hdbarcode": hdbarcode, "description": description };
  	
// 2nd argument is callback
getDescription(item.hdbarcode, function(upcDescrip){
  db.save(null, item, function (err, meta) {
    // This does not change item on line 1. Why?
    item.key = meta.key;
    sys.puts('saved ' + JSON.stringify(item) + ' as '+ meta.key);

    // tell client
    res.simpleJSON(200, { "key": item.key, "message": "Success!" });
    // key is undefined, because item.key was never set 
  });
});