Help with Item abilities

Hi! I have a problem with an item's abilities. I want the item to regain the mana of the hero at the same time that it damages the heroes's health.
I have created a new ability that is based on the unholy armor spell, and it works fine until I add another ability (Item Mana Regain (Greater) )to the item, then nothing happens.
Please help.

It seems like you can't have two abilities that must be casted on the same item. Just make a trigger that does the mana regain.

Alright, thanks. A question just, what type of action should I use in the trigger? I used Add ability but then the hero just got that ability, kinda strange....
Edit: I also tried to use the set mana to value action, but then it only sets the heroes mana to a specific value, I want it to work like this (Current mana of Triggering unit + 300).

Then use the (Current mana of Triggering unit + 300) as that value, you have the arithmetic function to add/substract/multiply/divide values, and then you just have to look up the function for "unit's current mana".

like this

I tried that before but didn't get it to work right. Oh well, it works now, so thanks everybody :).
Real nice place here.