Siphon Mana Problem

[1RingToRule]

Hey, this is a very simple problem but I can't seem to get this to work. I'm trying to modify the Siphon Mana ability so that it only gives mana and hit points to friendly units and can't be used against enemies. But the closest I've gotten is to make it completely useless so that it says I need to target a enemy unit when I try to use it on an ally, and that I need to target an allied unit when I use it on an enemy....

I believe that all I have to do is modify some of the abilities basic info but I have tried all the logical moves that I could think of already, so if any of you have any ideas I would be most thankful.

 

[Blade.dk2]

I don't have the time, nor the will to write this again, but check the following thread at The Jass Vault, should give you the solution.

http://www.wc3jass.com/viewtopic.php?t=2533