Loading random files

[Alan Nielsen]

I'm working on an experimental design in which figures will be displayed,
and the subjects given a choice of two words to describe the figure.

The figures, and words however, have to be randomly selected from my
database of figures and words

How would I go about having a new random figure loaded in a figure window
everytime a stack opened? Obviously, the same thing is needed for words;
can I have a button display a random word from a list of words?

Cheers