assign code to buttons

The difference between AS2 and AS3, aside from some function names and overall performance, is that you cannot assign code "on" a button in AS3 like you can in AS2, but you certainly can assign code to a button.  It gets a little more verbose to do so in AS3, but it easy enough to get used to doing. 

Pretty much like Amy just showed, you assign an event listener for the button and you assign an event handler function for that listener which gets called when the event is detected.  In Amy's case, she is going a step further to show that you could have that function working for all your buttons by checking which button dispatched the event.  But you could just as well have a separate function for each listener as long as you name them uniquely.

myButton.addEventListener(MouseEvent.CLICK, goToPage);

function goToPage(e:MouseEvent):void {

     var url:String;

    switch (e.currentTarget) {

            case (myButton):

               url = "http://www.yourdomain.com/page1"

               break;

             //other cases for other buttons

    }

    //your url navigation logic from above, using the url variable populated in the case statement

}