Trigger by package install

[Marek Simon <marek.simon@trustica.cz>]

Hi,
I am creating my own package and I need to create a trigger which will 
be activated, when other packages are installed/deinstalled. I found in 
manual, that trigger can be dependant on file change, but not on package 
change. How can I effectively bind the trigger with a whole package?
I can select a file from a package and bind the trigger with it, but 
there is about 100 packages I need to bind and I think it is not that 
"nice" debian way. There must be some "nicer" way.
Thanks to all.

Marek