Wanted: Button like the "Install"-Button on this board

[Chriss74]

Hi Forum,

in the hack-forums of vbulletin the visitors can click on the "Install"-Button to show, that they installed a particular hack. I'm searching for such a modification for my vb 3.0.1. Where can I find such a hack?

I want the "Install" button for an other purpose: on my board many meetings are arranged in threads in form of postings like "I will come!". It would be good, if the posters could klick on a button "I will come" (instead of "Install"). Later, if a member wants to sign off a meeting, he should only need to click on the same button again.

On the top of the thread, I want a list of the members, who clicked on the button. If a member signed off, that should be mentioned, too.

I think, that such a hack could be interesting for many differnet purposes.

Does such a hack already exist?

Thanks for any advice!
Greetings,
Chriss