New Spell Idea (Is it possible?)

Just a neat spell idea I had, I can think of many uses you could use with this.
It would be a spell that when cast leaves the affected area in a fog of war state even when you have units in it for a select period of time and you can still select the units but not see em (or something like that so you don't lose compleat control of them). I'm preety sure if it's possible that it would have to be JASS scripted, that is, if it is possible.
If you have worked with JASS before and think it may or may not work plz post!

Oh, it's possible. All the units under the fog would have to have their sight reduced or you'd have to apply fog of war (or visibility modifier) via triggers (it's preety simple though).

er... if you get this working would you let me know? Id love to use something like this...a great many uses...such as an orb of darkness? Drow anyone?