Previous Scene still shows under new scene - Scenes not clearing! Flash CS3 AS2

[COLOR=#333333][FONT=Segoe UI]I am a novice to Flash and AS2. I am creating a website for an art gallery. It has several menu buttons at the top. The buttons goto and play various scenes containing scripts/galleries which use xml to load images. When I click on gallery 1 button the gallery works fine, then if I click on gallery 2, everything works fine, but if I then click back on gallery 1, gallery 2 still displays underneath the gallery 1. The galleries themselves are AS2. How can I make it so that no matter which order the buttons are pressed, only the content that is called on from the frame that the button points to is shown. Thanks[/FONT][/COLOR]