Hi, at one point I generate n elements of dropdowns dynamically. Whenever I make a selection in any of those choices the others should also be updated, ie. the list of available choices needs to be altered. But I also need to update in place the "model" that is associated with each individual dropdown. Should I simply use IORefs for this purpose, or should I rather use a more functional code with the State Monad? Is there a tutorial or an example on how to use the State monad? Günther