Show - Hide A Div Based On A Cookie?

I have a script I am trying to use to show or hide a div id. It uses a cookie, set on link click, to remember if the div should be displayed or not.

It works, but I'm having two problems:

1) The function only shows/hides the first instance of the div, not all instances.

2) Reloading the page after an initial cookie set causes the div to always initially be displayed regardless of the last cookie value (cookie seems to automatically re-set itself to 'tutor-show').

Here is the code:

You can see it in action here: uomeds{dt}com/cbl/cbl-2.htm