Actionscript: Why do I get error when I create get x and set x in flash document class?

Message is 1024: Overriding a function that is not marked for override.

what does x and y represent for document 开发者_运维技巧class ? should I avoid to use x and y ?

The document class extends MovieClip or Sprite so the x and y properties are already declared and you should avoid using 'em.

They don't have any use in the document class.

The document class represents the stage and main timeline. It does not have an X or Y per se, but rather could be thought to supply the stage upon which all other objects derive their x and y's from.