How the heck do you add-on on Party, anway?

[eastbay]

I searched for this and came up empty. I see the re-buy button near Cashier in the lower right, but how the heck do you add-on?

eastbay [img]/images/graemlins/blush.gif[/img]

[stu-unger]

during the break it gives u the option. i believe it shows up it the same place the rebuy tab was b4 the break...