Event Notices & Users Online

[Missy Master]

What would be the best way to implement:

1. A brief pop up notice ( or any kind really, something like the message center would work too) that notifies users when something has happened, such as a pet selling, etc.


and 2.

How would you write the code to show the users actually logged in at the time --- I guess it would show on index.php.


Thanks!! I've tried on my own to figure these out and I'm still stumped.