I am extremely stupid when it comes to cookies. It seems like every time I see an example, it has so much extra stuff, I can't weed out what I need. So here I am, come to beg for a super simple session cookie (that may not be so simple).

When accessing the index page of my site, I have a small popup window that plays a song. In the popup is the control panel to pause or stop the music and a Close button to close the window. The problem is that every time you return to the index page, it loads again. I would like to give visitors the option of turning it off for the entire session, but have that cookie deleted when they leave the site, so they get the music again when they return.

If you could post a very simple cookie (and tell me what to do with it) I would be extremely grateful. Hopefully I can learn a few things from a straightforward example and I won't have to pester you again!
Thanks.