How to dectect loaded movieclips on stage

I am fairly new to actionscripting and I have to use AS2.0. So I am wondering how to dectect if all the desired movieclips have been loaded onto the stage.

For example I have externally loaded 6 movieclips onto the stage as a result of a click action. What I want to do is when all 6 movieclips have been loaded onto the stage I want to the then load a movieclip that says, “Congratulations, you have completed the course.” But I don’t know how to detect if all 6 movieclips have been loaded or not.

I’d appreciate any help anyone can provide.