[quoteSelect target path [/home/stolp]

The directory already exists and is not empty! Are you sure you want to install here and delete all existing files?
Press 1 to continue, 2 to quit, 3 to redisplay
1
press 1 to continue, 2 to quit, 3 to redisplay
1

Select the packs you want to install:



The first confirmation is for the above question (it is a dialog in GUI Mode), the second for actually starting the install in the selected directory.
The IzPack installer takes a generic approach for this so this looks a bit confusing.

Torsten

P.S.: I edited this answer after the first post, as the first one proved to be wrong.