Creating a Class that Removes a MovieClip

I would like to create a class that removes a movie clip as this is something that needs to be done frequently.

I have a button and in the library I have assigned it to the "Close" class (AS Linkage).

I created the following class:

package  {

    import flash.display.MovieClip;

    import flash.display.SimpleButton;

    import flash.events.MouseEvent;

    public class Close extends MovieClip

    {

        //ContructorCode

        public function Close()

        {

            closeButtonNow();

        }

        public function closeButtonNow():void

        {

            this.removeChild(this);

        }

    }

}

Depending on how I  play with the code I get the following errors:

1061: Call to a possibly undefined method removeChild through a reference with static type Close.

5000: The class"Close" must subclass 'flash.display.SimpleButton' since it is linked to a library symbol of that type.

What am I doing wrong? I know it's something simple but I don't fully  understand the use of "this".