Direct movement to point


I currently have a flash chatroom up and running but there is a minor snag. The only way I can explain is through demo. See:

EDIT: I made a very short video for those who do not wish to log into the chatroom - it shows the problem clearly. Loc:

Go in chat and click anywhere on screen. You will see the sprite move as the client describes “along a train track”. How can I just make the sprite move directly towards a point upon mouse click?

Thank you. It is probably very simple indeed I’m just not in a math thinking mode right now ;).