There is a probably a better way to handle this problem. I will make it so that maintaiing these lists are easier. for example, if you have more than 5 variables, it will not show only really long list, but maybe something like this:
VARNAME [ ____]
VARNAME2 [_____]
[select variable [\/]] (Add Restriction)
Clicking on Add restriction would add a new item to the window, so you could restrict it.
Make sensE?
