Basic motion with actionscript

It’s been a long time since I’ve done any work with actionscript, and alas I’ve forgotten nearly everything. I’ve tried to look for a tutorial that would explain basic animation with actionscript, but the one that I found on Kirupa was no longer there.

Basically I’d like to do this:

On the stage I have a movieclip and I’d like the movieclip to move along the x-axis to a certain point and then back to the starting point again. The moving speed of the movieclip should also be adjustable.

I know how to do this with motion tween, but I’d really like to know how to do this with actionscript.

Thanks a lot in advance.