[TxMt] basic dialog in ruby

[Piero D'Ancona]

Hi all.
Can someone point me to a basic example of
a dialog from inside a ruby code? My needs
are basic: at some point my code computes
a certain string; I want to check the string,
edit it by hand if necessary, and then continue.
So I just need something like the example in
Allan's screencast about tmDialog, only from
inside some ruby code in a TextMate command.

Thanks,
Piero