This script works great, but you need to remove the comment slashes on the console.println line, as below. Thanks to the original poster.
var d = event.target.dataObjects;
if (d != null)
for (var i = 0; i < d.length; i++) {
console.println("Data Object[" + i + "]=" + d[i].name);
event.target.removeDataObject(d[i].name);
}