Help with sharedobject playing banner once

here is my problem,
i have a flash banner on a layer in html that i want users to view only once, so the next thing the user visits, he wont be able to see the banner,BUT, there is a image/link to reveal/replay the animation.

Since im a newbie, i have no idea how this script runs, and how to delete the sharedobject to reveal it again

any help???

tnx in advance