Unit - Damge Area/Target

How does the
Unit - Damage Area
and the
Unit - Damage Target
work?

I've been using the Unit - Damage Area in an AoE spell, but somehow it doesn't deal damage to the units there xP

Can someone explain how to use the Damage Area/Target spells?

When ever i want to deal damage in a area i always select each target within the area and deal single damage to them, as i feel that i can control that alot more (ex. different dam according to thier healt or mana and so on).
But i dont have the WE at this comp at the moment, but i'll come back in a couple of hours with a reasonable awnser if no one else has already done that :)

plz post your trigger. else i can only think of that your target point isnt defined.