Hi, I used to do conditionals based on undefined all the time in AS 2. For example I would do a data look up and then cast the results to a class called foo. Then I could do a conditional if (foo == undefined) // go and do whatever as the data ovbiously doesn't exist or has not been recieved. Now in AS3 this method still works but I get a warning that the class cannot be undefined and undefined will be type coerced into a foo class. As I said it still wors so I'm not too fussed, but it's never good to see warnings!
Tim

