Look up addChild and removeChild in the live docs....it allows you to add and remove items from the stage
PHP Code:
openbtn0.addEventListener(MouseEvent.CLICK, openfunction, false, 0 , true);
closebtn0.addEventListener(MouseEvent.CLICK, closefunction, false, 0 , true);
function openFunction(e:MouseEvent):void{
addChild(movieClip0);
}
function closeFunction(e:MouseEvent):void{
movieClip0.parent.removeChild(movieClip0);
}