# Interface of a class that extends MovieClip

**URL:** https://forum.kirupa.com/t/interface-of-a-class-that-extends-movieclip/329663
**Category:** flash
**Created:** [September 28, 2012, 10:29am UTC](https://forum.kirupa.com/t/interface-of-a-class-that-extends-movieclip/329663 "2012-09-28T10:29:06Z")
**Posts on this page:** 1
**Page:** 1

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### Author: ![GiGaGiG](https://avatars.discourse-cdn.com/v4/letter/g/a88e57/32.png) [@GiGaGiG](https://forum.kirupa.com/u/GiGaGiG)
#### Post date: [September 28, 2012, 10:29am UTC](https://forum.kirupa.com/t/interface-of-a-class-that-extends-movieclip/329663/1 "2012-09-28T10:29:06Z")

</div>

I am instancing an interface IJohn of a class John that extends MovieClip: I am receiving the errors that tells me that “addEventListener” is an unknown method, obviously.  
How can I fix this without putting all EventDispatcher methods in IJohn and John?

Plus, if I try to addChild the interface instance it tells me I am trying to use a IJohn as a DisplayObject, as the interface does not know that it is implementing a MovieClip.  
So, how can I use the MovieClip properties through an Interface instance?

Thanks