Flash CS3 AS2 - When button clicked, previous screen can still be seen under new one

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I am a novice to Flash and AS2. I am creating a website for an art gallery. It has menu buttons at the top. The buttons goto and play various information or galleries. However when I click on the buttons the info is displayed as it should be, and if I click on them in order, everything works fine. But if I click to go back to a previous gallery for example, the gallery that I was viewing is also shown on the page underneath the new one. 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

Sorry I posted this twice… [/INDENT]
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