Thoughts about Dialogs

I'm wondering how you use the dialogs for a, lets say for a "buy menu".
Like if you make 1 trigger for every "dialog part"(e.i. Main Menu, Buy Menu, Buy Items Menu) and then one for when a dialog button is clicked for every "dialog part",
or if you make 1 trigger every player and so on and so on.
Use your imagination :D

I use Triggering Player so I don't need to create any more dialogs than I have to. I create one big trigger that has alot of If/Then/Else. If XButton is clicked, Then do X, and I continue on.

ok, but why doesn't it work if you do like this (it wont work for me atleast):
Using the same dialog var. on the Main Menu, then when a button is pressed, clear the same dialog var. adding some buttons and the showing it... and its still the same buttons and the same title as the first one :/
it works when i use different dialog vars.