By the way, you can have a look at the compreval plugin, at:
http://wp.berkano.net/downloads/
It does what you want, adding a preview function. (However, it does not work for me as for some reason translations into other languages do not work, and I am running a multilingual site).
I am looking for the same, but so far no luck…
I would appreciate some help on how to deal with the issue.
