Dynamic menus and button presses

New to the forum and I have set my self a new task. Learning dynaic menus properly.
I have worked on one which I am almost happy with but there are things wrong with it. (if anyone has any good tutorials or FLAs on this that would be great).
But my main problem is now simply just having a button so when you rollover it, it changes colour and when you click it it stays on that colour so you can see which button is currently active. How do people go about scripting buttons to work properly like this? I have this code but it runs into too many problems…

var my_color:Color = new Color(this);

Any help would be great.