This does not work as expected in multi session environment.

Cache object is scoped by application not by session or am I wrong ?

It won't work in a web farm or garden either. It's easily fixed if you have those environments, just use Session (out of process) instead.

But a great idea nevertheless. Thanks.

It will work in a "multi-session" environment because each button instance is cached according to it's id, which is a GUID.

Johnny is correct, the usage of the Cache object won't affect multiple users because I store a form-level guid in the cache, not a traditional key.

unfortunatly, he is also correct about the web farm/garden problem. In my gleefull haste, I had overlooked that problem. Using an out-of-roc SessionState as the store for the GUID would seem to work, but you'll of course lose the feature where the GUID is released via automatic cache removal after the script times out and the UnLoad override can't release it.

It seems to me that the implications of this mean that a person using a web farm would have to change the code to use Session instead of cache. bummer.

Maybe an out-of-proc cache is in order?

Cool. Sounds like something Amazon would patent :)

Marcie